Which of Newton's laws best explains why motorists should buckle-up mts64 /kd e z-u;ncu+irb+smz ,dpx24?

  When you sit on a chair, the r ri2c7r3q5 yeeesultant force on you is

  In the absence of an exl 3. m1rzz+vzvternal force, a moving object will

  When the rocket engines on the starship NO-PAIN-NO-GAIN are suddenly turned off,9,nga j1prl:9 m9irm d while traveling p1rjmr9 9d:gma9i,n lin empty space, the starship will

  A rocket moves through empty space in a straight line with constant ss*wumlag)((-mnet 6 mpeed. It is far from the gravitational effec( lt*mnwm(6e suga- )mt of any star or planet. Under these conditions, the force that must be applied to the rocket in order to sustain its motion is

  You are standing in a moving bus, facing forward, and you p :dqlr+k swrq)pw,33 suddenly fall forward. You can imply from t3psqrprlw+q,):wkd 3 his that the bus's

  You are standing in a moving bus, facing forward, and you soe5.qk izw -u*uddenly fall forward as the bus comes to an immediate suqi-.ko 5 e*zwtop. What force caused you to fall forward?

  A constant net force acts 7 i; ksg wr(w (9fbtjh7uqq8*oon an object. Describe the motion of the object.

  The acceleration of an object is inverse x99wxd:*rz mply proportional to

  A net force F accelerates a mass m with an acce+/xwxedc (+z0wmqan/ d(6x xrleration a. If the same net force is applied to mass qwmz+cxa0e6r xwxx + /d/n ((d2m, then the acceleration will be

  A net force F acts on a mass m and produces an acceleratio o.mx 9yjgjzlgcl+o6 (h*o:v9r 5i3gpn a. What acceleration results if a net force 2F actoh yz g6j+r3lvxcgo59i(:9g.lj pm*o s on mass 4m?

  If you blow up a balloon, and then release it, the balloon will fly awoc75 ,; 2ycntvxk7ab mb0i3sday. This is an il 0sdb325 x 7cto7ynbckivma,;lustration of

  Two cars collide head-on. At every moment during the collisiorm1q979ry q qxewb() fn, the magnitude of the force the first car exerts on the second is exactly equal to the magnitude of the force the second car exerts on the first.7x f9q )re1wr(b 9qymq This is an example of

  If you exert a force F ;m. mevkdqr.kf(v 7m (on an object, the force which the object exerts on you willm;fe.kd vmvrm(k 7q.(

  Action-reaction forcp.v v9t/e0 i)xmt 5vzjes

  Action-reaction forces aedjltoh d-+4.t08jhw re

  A 20-ton truck collides with a 1500--a r/n7-xrr z yx x o(i,:5b7u)kaevtxzq +v6olb car and causes a lot of damage to the car. Sincevto a/u ) -y ex zk +i,q7rxx(-7zxar:5ornbv6 a lot of damage is done on the car

  An object of mass m sits on a flat table. The Earth pulls c z k*1v27fs tx81witton this object with force mg, which we will call the action force. What is the reaction *i wt7cz28v1k1sxtft force?

  A child's toy is suspended from the ceiling by means of a string. The Earth puqd6.8cdlbt50,ir m ro ci09hvlls downward on the toy with its weight force of 8.0 N. If this i6 8mv0bi,dlo0irq .9cdthrc5 s the "action force," what is the "reaction force"?

  Your bat hits the ball pitched to you with a 1500-N instantaneous force. a6b /e5t 9lk/qwxhp1 p c,od6u The ball hits the bat with an instantaneous force, /5,9 axte wq kocdb6u6p/l 1phwhose magnitude is

State Newton's three l/z. +0 fnhrcpnaws.

  Mass and weight

  The acceleration due to gravity is lower on the Moon thani)haitsly;q : 0 b4w:1r+ bpkr on Earth. Which of the following is true about the mass and weight t) y:04: ia; rpiw+brl1khbsqof an astronaut on the Moon's surface, compared to Earth?

  An example of a force which acts at a distance ixy 2)q/ e:iaqls

  Who has a greater weight to mass ratio, a person weighing 400 N or a person wev2vx(2n)s czz igv2v2s(n )cz zxhing 600 N?

  A stone is thrown straight up. At the top of its path, the net force1m znrs g)z*d7 acting on dz)gz7mrns*1 it is

  A 20-N weight and a 5.0-N weight are dff4.f vso7g-ghxq -5 rropped simultaneously from the same height. hgr7xf.5ff --q osv g4 Ignore air resistance. Compare their accelerations.

  A brick and a feather fall to the earth at their rjx9uf+ kr9bh(w;u,ns o05 vwsespective terminal velocities. Which object expbvj9 n5ru,0o(w ;kshx9u +fsweriences the greater force of air friction?

  An object of mass m is hanging by a string from 2xm jtah)kl/,p-:cvbthe ceiling of an elevator. The elevator is moving u:m) 2l/vk-actx,hpjbp at constant speed. What is the tension in the string?

  An object of mass m is hanging by a string from the ceiling of an elevatoqr qqh 3r53lt.r. The elevator is moving upward, but slowing down. What is the tension in the strir3q5 3 qlqrt.hng?

  The force that keeps you from sliding on an icy sidewalk b0e-jax/ 9 fy nz-4x2e4 +gkd (cezb,uf7usbl is

  It's more difficult to start moving a heavy carton from rest than it is t(22+05 b chcf2otivqdqz7n gc o keep pushing (t27oc5 z2dq0h+ cn bi2vfqgcit with constant velocity, because

  A horizontal force accelerates a box frds)fu /9c6 t,;js)ko nld ll2kom rest across a horizontal surface (friction is present) at a constant rate. The experiment is repeated, and all conditions remain the same with t/l;slt2f,kjkldu c69so n d) )he exception that the horizontal force is doubled. What happens to the box's acceleration?

  A packing crate slides down an f7ucu7ngp- m 8 :2ypy4p5(l jdcyh )keinclined ramp at constant velocity. Thus we can deduce th(cyu mph7 pu cl :572-pgnykd48yejf)at

  A block of mass M slides down a frictionless plane inclined at an angledwk axh d1 +ei99xu:9t q with the horizontal. The normal reaction force exerted by the plane on the bloc:9thad+ ix91euwkdx9 k is

  A block of mass M slides down a frictionless /v1u lthe34rx plane inclined at an angle q with the horizontal. The normal vl eu3/ r4txh1reaction force exerted by the plane on the block is directed

  A block of mass M slides down a frictionless plane inclined .m l p fyhlb97mbk.94sat an angle q with the horizontal. The gravitationasm9.yb9 f.lh 7m4 klpbl force is directed

  Two toy cars (16 kg and 2.0 kg) are released sim- xxkc h 2pdmw/*o5o)qultaneously on an inclined plane that makes an angle of 30e w x*5 oqmpkwhc-x) 2do/ith the horizontal. Make a statement which best describes their acceleration after being released.

  An object sits on a frictionless surface. A 16-N ffy o01qyrsdv 22*d+ oforce is applied to the object, and it acceleraty r2foddq12ysf0 + v*oes at $2.0 \; m/s^2$. What is the mass of the object?

  A sports car of mass 1000 kg can accelerate from rest to 27 m/s in 77qm f2f7cnpdm4a p4/t .0 s. What is t /ma2 4cd4mtppfqf77nhe average forward force on the car?

  Starting from rest, a 4.0-kg body reaches a speed of 8.0 m/s in 2.0 s. What isb 5 e(2tooo nozoq;opxb;2:( i the net force acting( 2no(:2 oooot xib qb;op5ze; on the body?

  An antitank weapon fires a 3.00-kg rocket which a6y1s knh(f*+xz-znr s cquires a speed of 50.0 m/s after travelingz *1s6n+ysxzh-r fk (n
90.0 cm down a launching tube. Assuming the rocket was accelerated uniformly, what is the average force acted on it?

  If you push a 4.0-kg mass with the same force that you push a 10-kg maq /u92wr+jpe7:z, v uz c:mhdoss from re27+u:qz cvre,hpdwuz:o/9 jm st,

  What is the mass of a person who weighsd 8u wz2c2xzka 9x*u7i 110 lb?

  What is the mass of an object that weighs 250 N on the surface of the Ear1mp1e5f3 hklhth where the acceleratio ke lm3h1ph5f1n due to gravity is $9.80 \; m/s^2$?

  An object has a mass of 60 kw c6)d.(drne cg on the Earth. What is the mass of the object on the surfacen6rd(d c).c ew of the Moon where the acceleration due to gravity is only 1/6 of that on the Earth?

  Object A weighs 40 N on Earth, and object B weighs 40 N on the Mop*hwwfv k9w- 3on. The Moon'sw9kw*hw -3p vf gravity is one sixth of Earth's. Compare the masses of the objects.

  Sue and Sean are having a tug-of-war by m5h +vhu7x;llo3z5dzpulling on opposite ends of a 5.0-kg rope. Sue pulls with;u zlx5375m dlv +hzoh a 15-N force. What is Sean's force if the rope accelerates toward Sue at $2.0 \; m/s^2$?

  A stack of books rests onq nd/io0 c;wa6 a level frictionless surface. A force F acts on the stack, and it accelerai/naw;o6d c q0tes at $3.0 \; m/s^2$. A 1.0 kg book is then added to the stack. The same force is applied, and now the stack accelerates at $2.0 \; m/s^2$. What was the mass of the original stack?

  A person of weight 480 N stands on a scale in ancd imkb5) 0m-x elevator. What will the scale be reading when the elevdbxik-) 50mmcator is accelerating downward at $4.00 \; m/s^2$?

  A person on a scale rides in an elevator. If the mass of the person4y 7 -nxvem,en is 60.0 kg and the elevator accelerates d7-x,ne4ev mny ownward with an acceleration of $4.90 \; m/s^2$, what is the reading on the scale?

  A person on a scale ridev lxcyubn ,02s/( .mecs in an elevator. If the mass of the person is 60.0 kg and the elevator accelerates upward u0c, (elnxc /v.bm2yswith an acceleration of $4.90 \; m/s^2$, what is the reading on the scale?

  Two horizontal forces act on a 5.0-kgt7n4uw kjs w8e- 0s5zft00nks mass. One force has a magnitude of 8.0 N and is directed due north. The second force toward the eastf4z0 wtk nktn0es -0su8sj 5w7 has a magnitude of 6.0 N. What is the acceleration of the mass?

  An object of mass 6000 kg rests on the flatbed of a truck. /db 6lq. e: 4l+sw0ww749oeb qbyc risIt is held in place by metal brackets that can exert a maximum horizontal force of 9000 N. slb.6co0 l49bqywwi/ s :q4+7ed rwe b When the truck is traveling 15 m/s, what is the minimum stopping distance if the load is not to slide forward into the cab?

  An object of mass 6000 kg rests on the fl35sugw-/3vu we :ir9pcdj 4ja atbed of a truck. It is held in place by metal brack 4ep sjur-a3j39w 5:dvgwc/uiets that can exert a maximum horizontal force of 9000 N. When the truck is traveling 15 m/s, what is the minimum stopping time if the load is not to slide forward into the cab?

  In the Atwood machine shown in Fig. 4-1, if M = 12j( a 8mmaelt0.60 kg and m = 0.40 kg, what is the magnitude of the 8j(la2me m1atacceleration of the system? (Ignore friction and the mass of the pulley.)

  In the Atwood machine shown in Figb 2lu *dpq5+j.xrkp7n )iy1uc. 4-1, if M = 0.60 kg and m = 0.40 kg, what is the tension in the string? (Ignore friction and the157+. k ilnpc rbudjp)u2* qxy mass of the pulley.)

  A student pulls a box of books on a smz;c:3 ked(op mooth horizontal floor with a force of 100 N in a direction of ;p:cz(dekmo 3$37^{\circ}$ above the horizontal. If the mass of the box and the books is 40.0 kg, what is the acceleration of the box?

  A student pulls a box of books on a yq3pd+lkto9y fh mj 3vhm ;11,smooth horizontal floor with a force of 100 N in a direction of 37.0e above the horizontal. If the ma,q mh p11y3k9;mlotj v dh+yf3ss of the box and the books is 40.0 kg, what is the normal force on the box?

  A traffic light of weight 100 N is supported by two ropes as s gl .8tpd/6/fyjj9im )wm qmu+hown in Fig. 4-2. What are t8/j9m/ wqit. ygpf )j6+muldm he tensions in the ropes?

  In Fig. 4-2, if the tensions in the ropes are 50 N, what is the mass oy+ hgjp7+tny;uvc+ .uf the traffic ligh+j.y;h+cg+t vyuu p7nt?

  Two boxes of masses m and 2m are in contact with each otherxo ym v6e ro/zkj3f,03i 9lfd+ on a frictionless surface 6foyfl +v/jmozi93,k d er03x. (See Fig. 4-3.) What is the acceleration of the more massive box?

  Two boxes of masses m and 2m are in contact with each other bnc g*13pfno*+ ouot+ on a frictionless surface. (See Fig. 4-3o*o3n f*++bcop utg1n.) What is the net force on the more massive box?

  Two boxes of masses m and 2m are connected by a rope. (See Fig. 4-4.) If thet73 6 vrsb* b-zrtt)di forward force on the more massive box is F, what is ttzvr3bi rb- td7t) s6*he tension in the connecting rope?

  Two boxes of masses m and 2m are connecttvl8i,jrl:g74ulgbp5y/8n 7jyy o (d 2 shhv3ed by a rope. (See Fig. 4-4.) If the forward force on75:hur7s,g2(ih8/ dy 4ylljpyg3o 8b nvv jlt the more massive box is F, what is the acceleration of the less massive box?

Two boxes are connected by a cord running over a pulley as shown iiqj)dv,w2mx :wi9g fh)wf+ ;jn Fig. 4-5. Box I of i2 fi9)d)gwfjm,xh:q;wj +wvmass
8.0 kg rest on the top of the table; the coefficient of kinetic friction between box I and the table is 0.10. Box II has a mass of 15.0 kg.
(a) Draw the free-body diagrams for the two boxes, identifying all of the forces acting on each of the masses.
(b) Calculate the acceleration of the system.
(c) Calculate the tension in the cord.

  The coefficient of static and kinetic fric;yni ;*.pezgunu ;r)ihf; m 1htions between a 3.0-kg box and a desk are 0.40 and 0.30, respectively. What is the f);;nryz* ium; pughn.eih1 ;net force on the box when a 15 N horizontal force is applied to the box?

  The coefficients of static and kinetic frictions for plastic()-b okuc6 w.o;oixri on wood are 0.50 and 0.40,coi(ro-i x;)ku.b o6w
respectively. How much horizontal force would you need to apply to a 3.0 N plastic calculator to start it moving from rest?

  An object slides on a level surface in the +x direct nfr8 of4d.p)wion. It slows and comes to a stop with a cofd.r o)f4wp8n nstant acceleration of -$2.45 \; m/s^2$. What is the coefficient of kinetic friction between the object and the floor?

  A 10-kg box sitting on a horizul 8nu izib4mx9 4 y7toos99.gontal surface is pulled by a 5.0-N force. A 3.0-N frictzu84oi94iysml9o.7x9 tb ug nion force retards the motion. What is the acceleration of the object?

  A horizontal force of 5.0 N accelerates a 4.0-sis,hkw s: *f0qz7f a,kg mass, from rest, at a rate of $0.50 \; m/s^2$ in the positive direction. What friction force acts on the mass?

  During a hockey game, a puck is given an initial speed of 10 m/s. It slien vfo,z *)e (:gt( ,mgpceug1des 50 m on the icee gepm1f(gtu,*z:,nv o(g )ec before it stops. What is the coefficient of kinetic friction between the puck and the ice?

  During the investigation of a traffic accidgp;i) el.qnt7 ent, police find skid marks 90.0 m long. They determine the coefficiee)q7tl i n;.pgnt of friction between the car's tires and the roadway to be 0.500 for the prevailing conditions. Estimate the speed of the car when the brakes were applied.

  Two boxes of masses m and 3m are sta dr)nq j iapmz) o2njgii7152+cked. (See Fig. 4-6.) The surface between the more massive box and the horizontal surface is smooth and the surface between the boxes is rough. If the less massive box does not srn d1 m2iop)jazq5i+g)i jn72lide on the more massive box, what is the static friction force on the less massive box?

  Two boxes of masses m and 3m are stacked. (See Fig.dl*cj*mvh ub9+y (t ,0yvxlcl7:2 jzb 4-6.) The surface between the more massive box and the horizontal surface is smoouyhb* tz,v j db*yll+9lj7v( x0c mc2:th and the surface between the boxes is rough. If the less massive box does not slide on the more massive box, what is the coefficient of static friction between the boxes?

  An object is on a frictionless inclined plane. x97d *8 ry(evn xnxpa/ The plane is inclined at an angle o98ryn7 xexn vadp*(x/ f $30^{\circ}$ with the horizontal. What is the object's acceleration?

  A 10-kg mass slides down a flat hill that kajgpy /m6t 5ocg*) +kmakes an angle of $10^{\circ}$ with the horizontal. If friction is negligible, what is the resultant force on the sled?

  A mass is placed on a7t);hdkbpt y.h+ t;xa smooth inclined plane with an angle of $37^{\circ}$ to the horizontal. If the inclined plane is 5.0-m long, how long does it take for the mass to reach the bottom of the inclined plane after it is released from rest?

A block lies on a smooth inclined plane tiltedp(kgmh0p 8)yn at an angle of $35^{\circ}$ to the horizontal.
(a) Draw the free-body diagram for the block.
(b) Determine the block's acceleration as it slides down the inclined plane.
(c) If the block started from rest 8.5 m up the incline from its base, determine the block's speed when it reaches the bottom of the incline.
(d) How long did it take the block to reach the bottom of the inclined plane?

  A wooden block slides directly down an inclined plane, at a constant velocity ofu3walote/mj3 )uw 6+q 6.m6j3o)/wwu3 ael q t+u0 m/s.
What is the coefficient of kinetic friction, if the plane makes an angle of $25^{\circ}$ with the horizontal?

  An object with a mass m sli.y1 m6 1o*xe8vkzwuf kx- rra*des down a rough $37^{\circ}$ inclined plane where the coefficient of kinetic friction is 0.20. What is the acceleration of the object?

  An object with a mass m bc25are9 r.*wxsekbl27nj: xslides down a rough $37^{\circ}$ inclined plane where the coefficient of kinetic friction is 0.20. If the plane is 10 m long and the mass starts from rest, what will be its speed at the bottom of the plane?

  A bulldozer drags a log weighing 500 N along a rough surface. The ca0tqmv ure*86a ,wliy z:t1ol3 ble attached to the log m,*1yta emziv3u68:rl w tlo0qakes an angle of $30.0^{\circ}$ with the ground. The coefficient of static friction between the log and the ground is 0.500. What minimum tension is required in the cable in order for the log to begin to move?

A 25.0-kg box is released from rest on a rough inclined p(mx/c+z0a2jzcy ,. b -sacs egzk 3m.wlane tilted at an angle o m-ymcwacaz 0z + ,b3kz(s x2jc.e./sgf $33.5^{\circ}$ to the horizontal. The coefficient of kinetic friction between the box and the inclined plane is 0.200.
(a) Draw the free-body diagram for the box.
(b) Determine the force of kinetic friction acting on the box.
(c) Determine the acceleration of the box as it slides down the inclined plane.

  An object is placed on an inclined plane. The angle of incp91 lsbs yv;v)line is gradually increased until the object begins to slide. The angle at wp;yl 9 )svsbv1hich this occurs is q. What is the coefficient of static friction between the object and the plane?