Physics Unit6: Work and Energy - 51fly国际课程 (51fly.win)

1#

What is the correct unit of work expressed in SI aa ,vyj6h;zx /units?

A. $kg m/s^2$

B. $kg m^{2}/s$

C. $kg m^{2}/s^2$

D. $kg^2 m/s^2$

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

2#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

Can work be done on a systgi2 1ig4r6p+ ,uloctl em if there is no motion?

A. Yes, if an outside force is provided.

B. Yes, since motion is only relative.

C. No, since a system which is not moving has no energy.

D. No, because of the way work is defined.

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

本习题练习题目来源于51fly国际课程 (https://51fly.win)，学生可刷题练习，扫右侧二维码或加微信skysky1258，获取更多资料
教师可以抽题组卷或一键复制本试卷，布置为在线考试或在线作业，全自动判分成绩一键排序导出，省时省力

标记此题

3#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

If you push twice as hard against a stationary brick wall, the amount of gt o p+zq9+0el4fx0hml*i1unfx2o9r work yo+uxz0qlg +f9p 209xhe olf1it4rm*o nu do

A. doubles.

B. is cut in half.

C. remains constant but non-zero.

D. remains constant at zero.

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

4#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

A 50-N object was lifted 2.0 m vertica qup7 * fxdxnrt2l8,;rlly and is being held there. How much work is being done in holding the box in thiq, p;x*u xdnfrt78r2 ls position?

A. more than 100 J

B. 100 J

C. less than 100 J, but more than 0 J

D. 0 J

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

5#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

If you walk 5.0 m hori y1*zm vt2d:*.dyk ,yeenrhf )zontally forward at a constant velocity carrying a 10-N object, the amount of he 2:,1ytry*)vzdn ed k*my. fwork you do is

A. more than 50 J.

B. equal to 50 J.

C. less than 50 J, but more than 0 J.

D. zero.

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

6#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

A container of water is lifted /7t38pdjubev vertically 3.0 m then returned to its original posi/8 jpd3bv7ue ttion. If the total weight is 30 N, how much work was done?

A. $45 \; J$

B. $90 \; J$

C. $180 \; J$

D. No work was done.

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

7#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

Does the centripetal force actshvmjn 7 -wd;l 4gh)f1ing on an object do work on the object?

A. Yes, since a force acts and the object moves, and work is force times distance.

B. Yes, since it takes energy to turn an object.

C. No, because the object has constant speed.

D. No, because the force and the displacement of the object are perpendicular.

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

8#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

You throw a ball straight up. Compare the sil 4czenmqb 6etnc81x4; r p,;lgn of the work done by gravity while the ball goes up with the sign of the work done by gravity while it goes dow 1;,z4pq84exe nnt clcrlm6 b;n.

A. Work is + on the way up and + on the way down.

B. Work is + on the way up and - on the way down.

C. Work is - on the way up and + on the way down.

D. Work is - on the way up and - on the way down.

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

9#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

The area under the cudi+)s1 gzgz)hfb (si* rve, on a Force versus position (F vs. x) graph, represents+(g1 b*fdsi )z igsh)z

A. work.

B. kinetic energy.

C. power.

D. potential energy.

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

本习题练习题目来源于51fly国际课程 (https://51fly.win)，学生可刷题练习，扫右侧二维码或加微信skysky1258，获取更多资料
教师可以抽题组卷或一键复制本试卷，布置为在线考试或在线作业，全自动判分成绩一键排序导出，省时省力

标记此题

10#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

On a plot of Force versus position (F vs. x), what rabina( dj +,e/epresents the work done by the force Fnji,ade(+/ a b?

A. the slope of the curve

B. the length of the curve

C. the area under the curve

D. the product of the maximum force times the maximum x

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

11#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

The quantity $\frac{1}{2} \; mv^2$ is

A. the kinetic energy of the object.

B. the potential energy of the object.

C. the work done on the object by the force.

D. the power supplied to the object by the force.

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

本习题练习题目来源于51fly国际课程 (https://51fly.win)，学生可刷题练习，扫右侧二维码或加微信skysky1258，获取更多资料
教师可以抽题组卷或一键复制本试卷，布置为在线考试或在线作业，全自动判分成绩一键排序导出，省时省力

标记此题

12#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

If the net work done on an object is positi (sy *)opbmk5cve, then the object's kinetic energy

A. decreases.

B. remains the same.

C. increases.

D. is zero.

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

13#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

If the net work done on an object i,q6 f );nkkc:jyl8jyr8;vijq s negative, then the object's kinetic energy

A. decreases.

B. remains the same.

C. increases.

D. is zero.

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

14#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

If the net work done on an object is zero, then the objec4q7oc uf 3okp(t's kinetic energy

A. decreases.

B. remains the same.

C. increases.

D. is zero.

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

15#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

A truck weighs twice as much as a car, and is moving at twice the speed ofn ;i.:r;d 72zab w +sxj7zrjlm the car. Which statement is true about the truck's kinetic energy compared77a+; xr.;j rilds2zm b:jzwn to that of the car?

A. All that can be said is that the truck has more kinetic energy.

B. The truck has twice the kinetic energy of the car.

C. The truck has 4 times the kinetic energy of the car.

D. The truck has 8 times the kinetic energy of the car.

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

16#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

Car J moves twice as fast as car xv6 cw;n )whs: 22tydrK, and car J has half the mass of car K. The kinetic energy of car J, compared to car Ksx62wvd h)wt;rncy2: is

A. the same.

B. 2 to 1.

C. 4 to 1.

D. 1 to 2.

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

17#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

An object hits a waln0nxv puq6d 18l and bounces back with half of its original speed. What is the ratio of the unnp1q6v8 d0 xfinal kinetic energy to the initial kinetic energy?

A. \frac{1}{2} \;

B. 1/4

C. 2

D. 4

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

18#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

A brick is moving at a speed of 3 m/s and ad +gk q2pc1hr( pebble is moving at a speed of 5 m/s. If both objects have the same kinetic energy, what is tgd+hrk p(cq 21he ratio of the brick's mass to the rock's mass?

A. 25 to 9

B. 5 to 3

C. 12.5 to 4.5

D. 3 to 5

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

19#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

A 4.0-kg mass is moving with speed 2.0 m/s. f5f8chc u o30r82.fjkw1 ogtr A 1.0-kg mass is moving with speed 4.0 m/s. Both objects encounter the stcoh 3ffwc50g 81uj.r f2ko8 rame constant braking force, and are brought to rest. Which object travels the greater distance before stopping?

A. the 4.0-kg mass

B. the 1.0-kg mass

C. Both travel the same distance.

D. cannot be determined from the information given

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

20#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

You slam on the brakes of your car in a panic, and skid a cezw; dfli6c c6b 25. wn6q9cofdrtain distance on a straight, level road. If you had been65z d clfcb 6 cwd;92i.qwon6f traveling twice as fast, what distance would the car have skidded, under the same conditions?

A. It would have skidded 4 times farther.

B. It would have skidded twice as far.

C. It would have skidded 1.4 times farther.

D. It is impossible to tell from the information given.

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

本习题练习题目来源于51fly国际课程 (https://51fly.win)，学生可刷题练习，扫右侧二维码或加微信skysky1258，获取更多资料
教师可以抽题组卷或一键复制本试卷，布置为在线考试或在线作业，全自动判分成绩一键排序导出，省时省力

标记此题

21#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

A planet of constant mass orbits the Sun in an elliptdhsi(u2r -8x5jxawh 1zh t,uvq/o+ty 8i 6:pcical orbit. Neglecting any friction effects, what happens to the planet's th 2/w yj1:p68iquat -hv,85xr+ioh dcu(zxs kinetic energy?

A. It remains constant.

B. It increases continually.

C. It decreases continually.

D. It increases when the planet approaches the Sun, and decreases when it moves farther away.

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

本习题练习题目来源于51fly国际课程 (https://51fly.win)，学生可刷题练习，扫右侧二维码或加微信skysky1258，获取更多资料
教师可以抽题组卷或一键复制本试卷，布置为在线考试或在线作业，全自动判分成绩一键排序导出，省时省力

标记此题

22#

问答题 ( 1.0 分) 切至整卷模式搜藏此题

State the work-energy princi; l3 jqzbgq7pry*2a7d ple.

该题自我估分: (必填) (满分:1.0分)

绑定到本题的附件链接:
绑定到本题的上传图片: (问答题类型题目图片/附件必须插入上方文本框，否则会被移除题目绑定)

参考答案:

进入本题讨论区，参与讨论

标记此题

23#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

The quantity mgy is

A. the kinetic energy of the object.

B. the gravitational potential energy of the object.

C. the work done on the object by the force.

D. the power supplied to the object by the force.

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

24#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

The quantity $\frac{1}{2} \; kx^2$ is

A. the kinetic energy of the object.

B. the elastic potential energy of the object.

C. the work done on the object by the force.

D. the power supplied to the object by the force.

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

25#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

Is it possible for a systewur8/oubg0 - l(eawmj)ny :4qm to have negative potential energy?

A. Yes, as long as the total energy is positive.

B. Yes, since the choice of the zero of potential energy is arbitrary.

C. No, because the kinetic energy of a system must equal its potential energy.

D. No, because this would have no physical meaning.

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

26#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

An object is released from res,3tknb;xq hjl3pq3b eg039xn t a height h above the ground. A second object with four times the mass of the first if released from the same height. The potential energy of th gqnb3 p ,x3kltxhb0qj33e 9;ne second object compared to the first is

A. one-fourth as much.

B. one-half as much.

C. twice as much.

D. four times as much.

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

本习题练习题目来源于51fly国际课程 (https://51fly.win)，学生可刷题练习，扫右侧二维码或加微信skysky1258，获取更多资料
教师可以抽题组卷或一键复制本试卷，布置为在线考试或在线作业，全自动判分成绩一键排序导出，省时省力

标记此题

27#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

A 0.200-kg mass attached to the end c hcmxg+98uii u.,zv 2of a spring causes it to stretch 5.0 cm. If another 0.200-kg mass is added to the spring, th8v+,9x mc izu uh.c2gie potential energy of the spring will be

A. the same.

B. twice as much.

C. 3 times as much.

D. 4 times as much.

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

28#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

The total mechanical ene57z(n idhy m*zocc.h x4t3e:0 brqu1k uzl3 +irgy of a system

A. is equally divided between kinetic energy and potential energy.

B. is either all kinetic energy or all potential energy, at any one instant.

C. can never be negative.

D. is constant, only if conservative forces act.

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

本习题练习题目来源于51fly国际课程 (https://51fly.win)，学生可刷题练习，扫右侧二维码或加微信skysky1258，获取更多资料
教师可以抽题组卷或一键复制本试卷，布置为在线考试或在线作业，全自动判分成绩一键排序导出，省时省力

标记此题

29#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

An acorn falls from a tree. Compare skzka/cp2:b( 1zrmi) x lgh* (its kinetic energy K, to its potential energ lzxpi/rk*( z mc:(1bsakg)2h y U.

A. K increases and U decreases.

B. K decreases and U decreases.

C. K increases and U increases.

D. K decreases and U increases.

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

本习题练习题目来源于51fly国际课程 (https://51fly.win)，学生可刷题练习，扫右侧二维码或加微信skysky1258，获取更多资料
教师可以抽题组卷或一键复制本试卷，布置为在线考试或在线作业，全自动判分成绩一键排序导出，省时省力

标记此题

30#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

Describe the energy of a car driving up a hill+l(f llrca9( krcg8-g pmg-h*.

A. entirely kinetic

B. entirely potential

C. both kinetic and potential

D. gravitational

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

31#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

A lightweight object and a very hh+lpf.e g5h b 0x89vn9on4zgyeavy object are sliding with equal speeds along a level frictionless surface. They 0.zg+v o 9hf4ybg9pnnl xh e58both slide up the same frictionless hill. Which rises to a greater height?

A. The heavy object, because it has greater kinetic energy.

B. The lightweight object, because it weighs less.

C. They both slide to the same height.

D. cannot be determined from the information given

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

32#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

Consider two masses c onb-g4+hjk rjex*g4x5o );a $m_{1}$ and $m_{2}$ at the top of two frictionless inclined planes. Both masses start from rest at the same height. However, the plane on which $m_{1}$ sits is at an angle of $30^{\circ}$ with the horizontal, while the plane on which $m_{2}$ sits is at $60^{\circ}$. If the masses are released, which is going faster at the bottom of its plane?

A. $m_{1}$

B. $m_{2}$

C. They both are going the same speed.

D. cannot be determined without knowing the masses

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

本习题练习题目来源于51fly国际课程 (https://51fly.win)，学生可刷题练习，扫右侧二维码或加微信skysky1258，获取更多资料
教师可以抽题组卷或一键复制本试卷，布置为在线考试或在线作业，全自动判分成绩一键排序导出，省时省力

标记此题

33#

问答题 ( 1.0 分) 切至整卷模式搜藏此题

State the principle of conservatit 4d;b fd0eh9iq1ds(won of mechanical energy for conservative forces. fih 4e;d(sqb d1t09wd

该题自我估分: (必填) (满分:1.0分)

绑定到本题的附件链接:
绑定到本题的上传图片: (问答题类型题目图片/附件必须插入上方文本框，否则会被移除题目绑定)

参考答案:

进入本题讨论区，参与讨论

标记此题

34#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

A ball falls from the top of a building, throui+kr1 9 pw.gy 9f+6l apdkycfx)9l5kh gh the air (air friction is present), to the ground below. How does the kinetic energy (K) just before striking the c5pkhd a91lfr)k+yliwx6.k 9gy + pf9ground compare to the potential energy (U) at the top of the building?

A. K is equal to U.

B. K is greater than U.

C. K is less than U.

D. It is impossible to tell.

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

35#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

A ball drops some distance and gains 30 J of kinetic energy. Do2twd/n m1 1pssb-nhn33cci.h not ignore air resistance. How much . 1t -cd1inphh 3m/wncs23s bngravitational potential energy did the ball lose?

A. more than 30 J

B. exactly 30 J

C. less than 30 J

D. cannot be determined from the information given

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

36#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

A ball drops some distance and loses 30 J of gravitational potential energy. yjj/oprgegd).w, y/37vb/ w o Do not ignore air resistance. How o/bdj,/3epy y.7r g /) vwowjgmuch kinetic energy did the ball gain?

A. more than 30 J

B. exactly 30 J

C. less than 30 J

D. cannot be determined from the information given

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

本习题练习题目来源于51fly国际课程 (https://51fly.win)，学生可刷题练习，扫右侧二维码或加微信skysky1258，获取更多资料
教师可以抽题组卷或一键复制本试卷，布置为在线考试或在线作业，全自动判分成绩一键排序导出，省时省力

标记此题

37#

问答题 ( 1.0 分) 切至整卷模式搜藏此题

State the law of conservt: )9zayb-0ngk 5zu 6lfexz x:ation of energy.

该题自我估分: (必填) (满分:1.0分)

绑定到本题的附件链接:
绑定到本题的上传图片: (问答题类型题目图片/附件必须插入上方文本框，否则会被移除题目绑定)

参考答案:

进入本题讨论区，参与讨论

标记此题

38#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

The quantity Fd/t is1hbx61-lp nt m

A. the kinetic energy of the object.

B. the potential energy of the object.

C. the work done on the object by the force.

D. the power supplied to the object by the force.

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

39#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

What is the correct unit of power e;22 e lxrh:egexpressed in SI units?

A. $kg m/s^2$

B. $kg m^{2}/s^2$

C. $kg m^{2}/s^3$

D. $kg^2 m/s^2$

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

40#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

Of the following, which*6kd gbpyn0; 03mm nht is not a unit of power?

A. watt/second

B. newton-meter/second

C. joule/second

D. watt

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

41#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

Compared to yesterday, you did 3 times the work unsmg 8j1pt .+in one-third the time. To do so, your power oujn1u p gms+t.8tput must have been

A. the same as yesterday's power output.

B. one-third of yesterday's power output.

C. 3 times yesterday's power output.

D. 9 times yesterday's power output.

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

42#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

To accelerate your car ats1cbf),/infn6jw jd:umgjt 6s ; b :t4 a constant acceleration, the car's engine must

A. maintain a constant power output.

B. develop ever-decreasing power.

C. develop ever-increasing power.

D. maintain a constant turning speed.

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

43#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

An object is lifted vertically 2.0 m and -p.ch+ge(n2 ltaipe 8ab(zp2held there. If the object weighs 90 N, how much work was done in lifting it?a2b2tp+ .ph zncp8a(-( lgiee

A. $360 \; J$

B. $180 \; J$

C. $90 \; J$

D. $0 \; J$

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

44#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

You lift a 10-N physics book up in the air a distance of 1.0 m, at a constan ql3+hb8spem ;nbu3xyc6 9t lrlv19g* t velocity of 0.50 m/s. What is the work done by the weight of thlgllnqmt;yrcb vu p+39e9b8s3x 16h* e book?

A. +10 J

B. -10 J

C. +5.0 J

D. -5.0 J

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

45#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

A 500-kg elevator is pulled upwawqo7f9)8h ymprd with a constant force of 5500 N for a distance of 50.0 m. Wy8hw)97f m opqhat is the work done by the 5500 N force?

A. $2.75 \times 10^{5} \; J$

B. $-2.45 \times 10^{5} \; J$

C. $3.00 \times 10^{4} \; J$

D. $-5.20 \times 10^{5} \; J$

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

本习题练习题目来源于51fly国际课程 (https://51fly.win)，学生可刷题练习，扫右侧二维码或加微信skysky1258，获取更多资料
教师可以抽题组卷或一键复制本试卷，布置为在线考试或在线作业，全自动判分成绩一键排序导出，省时省力

标记此题

46#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

A 500-kg elevator is pulled upw22zxn ,haeji f 8-n:qxard with a constant force of 5500 N for a distance8: xhf2jqeanz,xn2-i of 50.0 m. What is the work done by the weight of the elevator?

A. $2.75 \times 10^{5} \; J$

B. $-2.45 \times 10^{5} \; J$

C. $3.00 \times 10^{4} \; J$

D. $-5.20 \times 10^{5} \; J$

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

本习题练习题目来源于51fly国际课程 (https://51fly.win)，学生可刷题练习，扫右侧二维码或加微信skysky1258，获取更多资料
教师可以抽题组卷或一键复制本试卷，布置为在线考试或在线作业，全自动判分成绩一键排序导出，省时省力

标记此题

47#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

A 500-kg elevator is pulled upward witrr7i r,ozh -yuzm+.u7e 3 jo8fh a constant force of 5500 N for a distance of 50.0 m. What is the net work done on thoyri87z.jr-ruf3hm , ez 7u+oe elevator?

A. $2.75 \times 10^{5} \; J$

B. $-2.45 \times 10^{5} \; J$

C. $3.00 \times 10^{4} \; J$

D. $-5.20 \times 10^{5} \; J$

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

本习题练习题目来源于51fly国际课程 (https://51fly.win)，学生可刷题练习，扫右侧二维码或加微信skysky1258，获取更多资料
教师可以抽题组卷或一键复制本试卷，布置为在线考试或在线作业，全自动判分成绩一键排序导出，省时省力

标记此题

48#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

A 30-N box is pulled 6.0 m up along nc7aw jc +ja.4a $37^{\circ}$ inclined plane. What is the work done by the weight (gravitational force) of the box?

A. $-11 \; J$

B. $-1.1 \times 10^{2} \; J$

C. $-1.4 \times 10^{2} \; J$

D. $-1.8 \times 10^{2} \; J$

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

49#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

A 4.00-kg box of fruit slides 8.0 m down w19(8a pmscmi a ramp, inclined at $30^{\circ}$ from the horizontal. If the box slides at a constant velocity of 5.00 m/s, what is the work done by the weight of the box?

A. $157 \; J$

B. $-157 \; J + 78.4 \; J$

C. $78.4 \; J$

D. $-78.4 \; J$

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

50#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

Matthew pulls his little sister Sarah in a sled on an icy surface (assume no fri3*oh. bldfh)g ction), with a force of 60.) *.lg3bhfohd 0 N at an angle of $37^{\circ}$ upward from the horizontal. If he pulls her a distance of 12.0 m, what is the work done by Matthew?

A. $185 \; J$

B. $433 \; J$

C. $575 \; J$

D. $720 \; J$

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

51#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

A force moves an object in the direction of the force. :nbosm: d83z nxdz-5 vThe graph in Fig. 6-1 shows the force versus the object's position. Find the8b z-n53ddxzv:nmo s : work done when the object moves from 0 to 2.0 m.

本题所包含的其它图片:

A. $20 \; J$

B. $40 \; J$

C. $60 \; J$

D. $80 \; J$

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

本习题练习题目来源于51fly国际课程 (https://51fly.win)，学生可刷题练习，扫右侧二维码或加微信skysky1258，获取更多资料
教师可以抽题组卷或一键复制本试卷，布置为在线考试或在线作业，全自动判分成绩一键排序导出，省时省力

标记此题

52#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

A force moves an object in the direction of the force.yiz:uzq 2 ml(6 The graph in Fig. 6-1 shows the force versus the object's position. Find tm(z 6:ui 2qlyzhe work done when the object moves from 2.0 to 4.0 m.

本题所包含的其它图片:

A. $20 \; J$

B. $40 \; J$

C. $60 \; J$

D. $80 \; J$

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

53#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

A force moves an object (xm .x+nk7li2 uxpr 0yin the direction of the force. The graph in Fig. 6-1 shows the force versus the object's position.(0mxx i nyxkp+lu 2.r7 Find the work done when the object moves from 4.0 to 6.0 m.

本题所包含的其它图片:

A. $20 \; J$

B. $40 \; J$

C. $60 \; J$

D. $80 \; J$

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

本习题练习题目来源于51fly国际课程 (https://51fly.win)，学生可刷题练习，扫右侧二维码或加微信skysky1258，获取更多资料
教师可以抽题组卷或一键复制本试卷，布置为在线考试或在线作业，全自动判分成绩一键排序导出，省时省力

标记此题

54#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

A force moves an obje v q/pwp;mp1)oct in the direction of the force. The graph in Fig. 6-1 shows the force versus the obp) /o1wp mp;vqject's position. Find the work done when the object moves from 0 to 6.0 m.

本题所包含的其它图片:

A. $20 \; J$

B. $40 \; J$

C. $60 \; J$

D. $80 \; J$

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

55#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

A horizontal force of 200 N is applied to mo86l/zh0e4w+ pejfk k rve a 55-kg cart (initially at rest) across a 10 m level surface. What is the final kinetic energy of the car +8 z6fw4je/eh0kpk lrt?

A. $1.0 \times 10^{3} \; J$

B. $2.0 \times 10^{3} \; J$

C. $2.7 \times 10^{3} \; J$

D. $4.0 \times 10^{3} \; J$

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

56#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

A horizontal force of 2uril lb9,mrex44 b p6;00 N is applied to move a 55-kg cart (initially at rest) across a 10 m level surface. What is the final speed r im, le4;rxp 46bu9lbof the cart?

A. 73 m/s

B. 36 m/s

C. 8.5 m/s

D. 6.0 m/s

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

57#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

A 10-kg mass is moving with a speed of 5.0 m/s. 82kge, o 7aucsHow much work is required to stop the mass?,g8ocsu7a k2e

A. $50 \; J$

B. $75 \; J$

C. $100 \; J$

D. $125 \; J$

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

58#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

If it takes 50 m to stop a car initially moving pw7)-s ddiwzo,jsrfak0y2p6 0c7,wq at 25 m/s, what distance is required to stop a car moving at 50 m/s under the s q- ww2,a)j07 do0c7ssz 6ify wp,kdprame condition?

A. $50 \; m$

B. $100 \; m$

C. $200 \; m$

D. $400 \; m$

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

59#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

A spring-driven dart gun propels a 10-g dart. It is cocked by exerting a fo,h1vzf3.gc2 c gs9ilorce of 20 N over a distance of 5.0 cm. With what speed will the dart leave the gun, assuming the spring has negli.v9 lgf,z3g 2cc1soh igible mass?

A. 10 m/s

B. 14 m/s

C. 17 m/s

D. 20 m/s

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

60#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

A 100-N force has a horizontal component of 80 N and a vertical component of 60 *. 5. vyvp5oarrulx 2mN. The force i5 mu. .v2xyr pvar*o5ls applied to a box which rests on a level frictionless floor. The cart starts from rest, and moves 2.0 m horizontally along the floor. What is the cart's final kinetic energy?

A. $200 \; J$

B. $160 \; J$

C. $120 \; J$

D. zero

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

本习题练习题目来源于51fly国际课程 (https://51fly.win)，学生可刷题练习，扫右侧二维码或加微信skysky1258，获取更多资料
教师可以抽题组卷或一键复制本试卷，布置为在线考试或在线作业，全自动判分成绩一键排序导出，省时省力

标记此题

61#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

An arrow of mass 20 g is shot ho:olz9a5r9k oy f/ ja8srizontally into a bale of hay, striking the hay with a velocity of 60 m/s. It penetrates a depth of 20 cm beforey/9 lk sfzara5j: o8o9 stopping. What is the average stopping force acting on the arrow?

A. $45 \; N$

B. $90 \; N$

C. $180 \; N$

D. $360 \; N$

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

62#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

A 15.0-kg object is moved from a height of 7.00 cxh5 3cqvc9/. 5jbcfctrz(z.m above a floor to a height of 13.0 m .ccq 3 fcvj(5c5/ztc h.xb9rzabove the floor. What is the change in gravitational potential energy?

A. zero

B. 1030 J

C. 1176 J

D. 1910 J

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

63#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

A 400-N box is pushed up an inclined plane. The plane is 4.0 m long and r*u1ic sik,y lfj.t8(xuy 9 3enwnx3 .yises 2.0 m. If the plane is k x8*c .inulye1,j9 (yystx.3fn3u iw frictionless, how much work was done by the push?

A. $1600 \; J$

B. $800 \; J$

C. $400 \; J$

D. $100 \; J$

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

64#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

A 10-kg mass, hung ontxs-ua rarf li5t )jwv5v sbh. a/7):,po a spring, causes the spring to stretch 2.0 cm. What is the sprr wa x7:v/ ssl5ath-r 5)av)if, jb.puing constant?

A. $4.9 \times 10^{3} \; N/m$

B. $5.0 \times 10^{3} \; N/m$

C. 20 N/m

D. 2.0 N/m

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

65#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

A spring is characterized by a spring constant of 60 .t-bi2 qs .5iknoa4kmN/m. How much potential energy does it st.mk biin5ko-4saq t.2ore, when stretched by 1.0 cm?

A. $3.0 \times 10^{-3} \; J$

B. $0.30 \; J$

C. $60 \; J$

D. $600 \; J$

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

66#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

Calculate the work required to compress an initially uncompressed spriid12xuejzb )f2 oem5xq9ku. ojl,549v5t fjd ng with a spring )z9b,du 9fe k5q4juj ljx.e5d imotv2x2o1f5constant of 25 N/m by 10 cm.

A. $0.10 \; J$

B. $0.13 \; J$

C. $0.17 \; J$

D. $0.25 \; J$

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

67#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

What work is required to stretch a spring of spring consta 7tx ;v7,tbdbcnt 40 N/m from x = 0.20 m to v7t b;d7bcx,t0.25 m? (Assume the unstretched position is at x = 0.)

A. $0.45 \; J$

B. $0.80 \; J$

C. $1.3 \; J$

D. $0.050 \; J$

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

68#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

A spring with a sprin3nkijmh g: d1+g constant of 15 N/m is initially compressed by 3.0 cm. How much work is req g1mkni+3h :djuired to compress the spring an additional 4.0 cm?

A. $0.0068 \; J$

B. $0.012 \; J$

C. $0.024 \; J$

D. $0.030 \; J$

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

69#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

A 60-kg skier starts from rest from the top of5-c 2jb e:jp)p woake6 a 50-m high slope. What is the spee p5cwo:b 2)6pjke jea-d of the slier on reaching the bottom of the slope? (Neglect friction.)

A. 22 m/s

B. 31 m/s

C. 9.8 m/s

D. 41 m/s

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

70#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

A skier, of mass 40 kg, pushes off the top z)sehna7(m pq *ai:4q1z gif:of a hill with an initial speed of 4.0 m/s. Neglecting fricapq4:fhq 7:i m1nzi)sagz*e (tion, how fast will she be moving after dropping 10 m in elevation?

A. 7.3 m/s

B. 15 m/s

C. 49 m/s

D. 196 m/s

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

71#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

An object slides down a frictionless inclined plane. At the bottomna+4o c1x0 ibql r*-5i r lwrd2-e. +gyma:kzt, it has a speed4:g1lr .-z m+2ynqa dkc x5 b+o e-awitl0*irr of 9.80 m/s. What is the vertical height of the plane?

A. $19.6 \; m$

B. $9.80 \; m$

C. $4.90 \; m$

D. $2.45 \; m$

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

72#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

A 1.0-kg ball falls i3k :a,m- ,zun/rtg1p10r ccry:ni duto the floor. When it is 0.70 m above the floor, its potential energy exactly equals its k/a,g0m:: -1pr inr niud3yu t1cr,zc kinetic energy. How fast is it moving?

A. 3.7 m/s

B. 6.9 m/s

C. 14 m/s

D. 45 m/s

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

本习题练习题目来源于51fly国际课程 (https://51fly.win)，学生可刷题练习，扫右侧二维码或加微信skysky1258，获取更多资料
教师可以抽题组卷或一键复制本试卷，布置为在线考试或在线作业，全自动判分成绩一键排序导出，省时省力

标记此题

73#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

A toy rocket, weighizi r 7.s4n bw;byo)s +6fj,tcrng 10 N, blasts straight up from ground level with a kinetic energy of 40 J. At the exact top of its trajectory, its total mechanical energy is 140 J. To what vertics6cz,onw br; bi.74t )rys+fjal height does it rise?

A. $1.0 \; m$

B. $10 \; m$

C. $14 \; m$

D. $24 \; m$

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

本习题练习题目来源于51fly国际课程 (https://51fly.win)，学生可刷题练习，扫右侧二维码或加微信skysky1258，获取更多资料
教师可以抽题组卷或一键复制本试卷，布置为在线考试或在线作业，全自动判分成绩一键排序导出，省时省力

标记此题

74#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

A projectile of mass m leaves the ground with a kineti xi m(h7pa4p1nc energy of 220 J. At the highest point in its trajectory, its kinetic e4nx (mh1p ipa7nergy is 120 J. To what vertical height, relative to its launch point, did it rise?

A. $\frac{220}{mg} \; m$

B. $\frac{120}{mg} \; m$

C. $\frac{100}{mg} \; m$

D. Impossible to determine without knowing the angle of launch

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

75#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

A roller coaster starts from rest at a point 45 m above the bottom -f)3dx/s +pt.af md fdof a dip (See Fig. 6-2). Neglect friction, what will be ttd-+afm.dd/f 3spx )fhe speed of the roller coaster at the top of the next slope, which is 30 m above the bottom of the dip?

本题所包含的其它图片:

A. 14 m/s

B. 17 m/s

C. 24 m/s

D. 30 m/s

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

76#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

A roller coaster starts with a speed of 5.0 m/s at a 11xy.o4h1 iu;hotyubpoint 45 m above the bottom of a dip (See Fig. 6-2). Neglect friction, what will be the speed of the roller coaster at the top of the next slope, 4x1ot ob ihh1yy;.1uuwhich is 30 m above the bottom of the dip?

本题所包含的其它图片:

A. 12 m/s

B. 14 m/s

C. 16 m/s

D. 18 m/s

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

77#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

A roller coaster starts at a point 30 m above the b39tvr tgh,r 7aottom of a dip with a speed of 25 m/s (See Fig. 6-2). Neglect friction, what will be the speed of the roller coaster at the top of the next slope, which is 45 m above the bottom of trtr,3tvah g 97he dip?

本题所包含的其它图片:

A. 14 m/s

B. 16 m/s

C. 18 m/s

D. 20 m/s

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

78#

( 1.0 分) 切至整卷模式搜藏此题

What is the minimum speed of the ball at the bote+1p ;deo ncr9*u5.wa .uaqt7b wz2gotom of its swing (point

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

79#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

A:2.2 m/s

A. 3.1 m/s

B. 4.4 m/s

C. 4.9 m/s

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

本习题练习题目来源于51fly国际课程 (https://51fly.win)，学生可刷题练习，扫右侧二维码或加微信skysky1258，获取更多资料
教师可以抽题组卷或一键复制本试卷，布置为在线考试或在线作业，全自动判分成绩一键排序导出，省时省力

标记此题

80#

( 1.0 分) 切至整卷模式搜藏此题

难度:2

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

81#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

A pendulum of length 50 cm is pulled 30 cm away from the vertical axis ,u5j2nuqam ro8gymx zr- k0p5(6b+mqand released from rest. What will be its speeq5ab 8g ,5xm q6-2pkumo+0j(ru rz ynmd at the bottom of its swing?

A. 0.50 m/s

B. 0.79 m/s

C. 1.2 m/s

D. 1.4 m/s

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

82#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

A 1500-kg car moving at 25 m/s hits an initially ux ,: r7,o ,-( knlemwyc.nbozxncompressed horizontal spring with spring constant ,,( oln7ko x:b,cyzrmw.e- xnof $2.0 \times 10^6 \; N/m$. What is the maximum compression of the spring? (Neglect the mass of the spring.)

A. $0.17 \; m$

B. $0.34 \; m$

C. $0.51 \; m$

D. $0.68 \; m$

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

本习题练习题目来源于51fly国际课程 (https://51fly.win)，学生可刷题练习，扫右侧二维码或加微信skysky1258，获取更多资料
教师可以抽题组卷或一键复制本试卷，布置为在线考试或在线作业，全自动判分成绩一键排序导出，省时省力

标记此题

83#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

A driver, traveling at w *ya jt ksh*p81 5oggc(a/f,i70djqy 22 m/s, slows down her 2000 kg car to stop for a red light. What work is done by the friction force ay7so apj hc 5k8yfd*/j1qt,*w( igg0against the wheels?

A. $-2.2 \times 10^{4} \; J$

B. $-4.4 \times 10^{4} \; J$

C. $-4.84 \times 10^{5} \; J$

D. $-9.68 \times 10^{5} \; J$

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

84#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

The kinetic friction force between a 60.0-kg objectx26k:ns zl/mm and a horizontal surface is 50.0 N. If the initial speed of the:6 ms/x2 nmkzl object is 25.0 m/s, what distance will it slide before coming to a stop?

A. $15.0 \; m$

B. $30.0 \; m$

C. $375 \; m$

D. $750 \; m$

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

85#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

A 12-kg object is moving on a rough, leveq18:k1t ovlf ol surface. It has 24 J of kinetic energy. The friction force on it is a constant 0.50 N. How far will it slidel8vq : o1fot1k?

A. $2.0 \; m$

B. $12 \; m$

C. $24 \; m$

D. $48 \; m$

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

86#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

A force of 10 N is applied horizontally tnws ;.+ 2(cdrlfwri,v o a 2.0-kg mass on a level surface. The coefficient of kinetic friction between the mass and the surface is 0.20. If the mass is moved a distance of 10 m, wha ws(+wc.drl,;frivn2 t is the change in its kinetic energy?

A. $20 \; J$

B. $39 \; J$

C. $46 \; J$

D. $61 \; J$

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

87#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

A 60-kg skier starts from rest from the top of a 50-m hig:bqr4no 9b:+8a6ufculp skj+wl . *cfh slope. If the work done by frictio6s+br a p94 b+fq:k8ulf ccnlj:o. *uwn is $-6.0 \times 10^{3} \; J$, what is the speed of the skier on reaching the bottom of the slope?

A. 17 m/s

B. 24 m/s

C. 34 m/s

D. 31 m/s

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

88#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

An 800-N box is pushed up an inclined plane. xxop3ve+ri,* The plane is 4.0 m long and rises 2.0 m. It requvr3 ,eio+ x*pxires 3200 J of work to get the box to the top of the plane. What was the magnitude of the average friction force on the box?

A. $0 \; N$

B. non-zero, but less than 400 N

C. $400 \; N$

D. greater than 400 N

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

本习题练习题目来源于51fly国际课程 (https://51fly.win)，学生可刷题练习，扫右侧二维码或加微信skysky1258，获取更多资料
教师可以抽题组卷或一键复制本试卷，布置为在线考试或在线作业，全自动判分成绩一键排序导出，省时省力

标记此题

89#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

A 2.0-kg mass is released from rest at thgw hhbq . 9otn:0fk4k-e top of a plane inclined at 20e above horizontal. The coefficient of kinetic friction between the mass and the plane is 0.20. What will be the speed of the mass afterh.wq bf th94g -onkk0: sliding 4.0 m along the plane?

A. 2.2 m/s

B. 3.0 m/s

C. 3.5 m/s

D. 5.2 m/s

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

90#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

A 30.0-N stone is dropped from a height of 10m8wdu8j3/4 d0wo alhm.0 m, and strikes the ground with a velocity of 7.00 m/s. uj/0ld84 wo3w8 hmadm What average force of air friction acts on it as it falls?

A. $22.5 \; N$

B. $75.0 \; N$

C. $225 \; N$

D. $293 \; N$

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

91#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

At what rate is a 60.0-kg boy using energy when he runs up a flight of st km.6 ao.ps+yrairs 10.0-m high, ik.s6.m+ yap ron
8.00 s?

A. $75.0 \; W$

B. $735 \; W$

C. $4.80 \; kW$

D. $48 \; W$

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

92#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

A 10-N force is needed to move an object with a constant velocity of 5.0 c1 b23wl8c:/kgoah a qm/s. What pcwqa:2c1 gb8k3ha/l o ower must be delivered to the object by the force?

A. $0.50 \; W$

B. $1.0 \; W$

C. $50 \; W$

D. $100 \; W$

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

93#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

How many joules of energy are used by a 1.0 hp 6g3ct 0:xoacf motor that runs for 1.0 hr? (1 hp =fxc30g t:ac6o 746 W)

A. $3.6 \times 10^{3} \; J$

B. $2.7 \times 10^{6} \; J$

C. $4.5 \times 10^{4} \; J$

D. $4.8 \; J$

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

94#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

A cyclist does work at the rate of 500 W while riding.1 lh fbe(yessw2x 4)2j How much force does her foot push with when she is trs 22w1 heey)f 4j(slxbaveling at 8.0 m/s?

A. $31 \; N$

B. $63 \; N$

C. $80 \; N$

D. $4000 \; N$

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

95#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

A 1500-kg car accelerates from 0 to 25 m/s in 7.0 s. What is the avera2/u s4mj3tyw age power delivered by the engine? (1 hp = sm /y2uajwt34 746 W)

A. $60 \; hp$

B. $70 \; hp$

C. $80 \; hp$

D. $90 \; hp$

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

本习题练习题目来源于51fly国际课程 (https://51fly.win)，学生可刷题练习，扫右侧二维码或加微信skysky1258，获取更多资料
教师可以抽题组卷或一键复制本试卷，布置为在线考试或在线作业，全自动判分成绩一键排序导出，省时省力

账号		自动登录	找回密码
密码			立即注册

网页聊天 (离线可收发)

加微信咨询 (申请一对一课程辅导，加本站学习交流群）

电话咨询：

发帖咨询：

查看帮助：

未使用图片

本次作答已使用

1	2	3	4	5	6	7	8	9	10
11	12	13	14	15	16	17	18	19	20
21	22	23	24	25	26	27	28	29	30
31	32	33	34	35	36	37	38	39	40
41	42	43	44	45	46	47	48	49	50
51	52	53	54	55	56	57	58	59	60
61	62	63	64	65	66	67	68	69	70
71	72	73	74	75	76	77	78	79	80
81	82	83	84	85	86	87	88	89	90
91	92	93	94	95

1	2	3	4	5	6	7	8	9	10
11	12	13	14	15	16	17	18	19	20
21	22	23	24	25	26	27	28	29	30
31	32	33	34	35	36	37	38	39	40
41	42	43	44	45	46	47	48	49	50
51	52	53	54	55	56	57	58	59	60
61	62	63	64	65	66	67	68	69	70
71	72	73	74	75	76	77	78	79	80
81	82	83	84	85	86	87	88	89	90
91	92	93	94	95

1	2	3	4	5	6	7	8	9	10
11	12	13	14	15	16	17	18	19	20
21	22	23	24	25	26	27	28	29	30
31	32	33	34	35	36	37	38	39	40
41	42	43	44	45	46	47	48	49	50
51	52	53	54	55	56	57	58	59	60
61	62	63	64	65	66	67	68	69	70
71	72	73	74	75	76	77	78	79	80
81	82	83	84	85	86	87	88	89	90
91	92	93	94	95