Which of Newton's laws best explains why motorists sn:p( pxqz6:td3yxbh 7hould buckle-up?

  When you sit on a chair, the resultant force 5+9pl xy insoz5be n8)f;9fns u c*xk1d8y/ston you is

  In the absence of an external force, a moving oby-qw54 pnae *nject will

  When the rocket engines on the stars at:flu3 ec3r,hip NO-PAIN-NO-GAIN are suddenly turned off, while traveling in empty space, the starsh :uer3,clft 3aip will

  A rocket moves through empty space in a straight line with constant 4uu pt. c23surup* ll)sim*c9speed. It is far from the gravitational effect of any star or planet. Under these conditions, the force that must be applied to the rocket in order to sustainp3uurc.cu *ml p4st2u*s9l i) its motion is

  You are standing in a moving bus, facing forward, w4 z, m0i xe9lq0m2gydand you suddenly fall forward. You can imply from thiidz9w4l20qy0 x,mg mes that the bus's

  You are standing in a moving bus, facing fo0jhxg0*p vqiv bnr2d *3a g3m7rward, and you suddenly fall forward as the bus comes to an immej *0q*irnh v0v a233gdmxgb7p diate stop. What force caused you to fall forward?

  A constant net force acts on an object. Descrix2utsk,5l4aox t1r i ;,a-fp nbe the motion of the object.

  The acceleration of an object is inversely pzn i:9g/o1knj roportional to

  A net force F accelerates a mass m with an acceler1(sgeh y o6kh.ei9x p8ation a. If the same net force is applied to massh 6x9 es.io(hpe81ygk 2m, then the acceleration will be

  A net force F acts on a ma v0a3gd))gtefss m and produces an acceleration a. What acceleration results if a net )e3)0 tgvfda gforce 2F acts on mass 4m?

  If you blow up a balloon, and then rel0 bj+j wzb(:m8q9xqximt q)4lease it, the balloon will fly away. This is an illustration o4)9 jjbm +qwm 8xqzl xib(tq:0f

  Two cars collide head-on. At everh ln;:uh, rjx2hv9ls*y moment during the collision, 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 x ruh:vl9*jh;h s,nl 2on the first. This is an example of

  If you exert a force F on an object, the force7rhbcet4 -c*;wu b+o p which the object exerts on you will +; c-bwc*pert4bou 7h

  Action-reaction forces* kmn4 1c6o4ldg /sulx

  Action-reaction forces a: f,b xlxsa1c:p+,w,j5 zgs;kd *yenm re

  A 20-ton truck collides with a 1500-lb car and cak +mx6 l;zyvl(x5m i*v:fsl m5uses a lot of damage to the car. Since a lot of damage is yf(k xx:l6 sm5;+*liv vm5l mzdone on the car

  An object of mass m sits on a cs )2d(q4q aw)ez/s5 rei b*rlflat table. The Earth pulls on this object with force mg/dsb 2 azlws4i c qq)e*)er5r(, which we will call the action force. What is the reaction force?

  A child's toy is suspendzj92 k8sqvv;n ed from the ceiling by means of a string. The Earth pulls downward on the toy with i8v;nz9 2vqk jsts weight force of 8.0 N. If this is the "action force," what is the "reaction force"?

  Your bat hits the ball pitched to you with a 1500-N instantav iek;z(vq( 6j,,e mtp*p1rlmneous force. The ball hits the bat with an instantaneous forlp ti(m*vkezem vp61jr;,q,(ce, whose magnitude is

State Newton's three laws.9 brlxqrkd9p( x e1 .g7:d5qtd

  Mass and weight

  The acceleration due to gravity is lower on the Moonpe;n/jrie + 7 qv+sr6d than on Earth. Which of the following is true about the mass and weight of an astronaut on the Moone q7dv r+is;p +jr/ne6's surface, compared to Earth?

  An example of a force which acts at a dist*js +i2qwzj2)rk 1m3 a3rzoebance is

  Who has a greater weight to mass ratio, a person weighing 400 N or a person wei.e,lcvbis ,6g5ndkt3( ( z e8om,onhf ghing 600 n nt3c8(zid5bs,e( m.e lf6h,vgk,ooN?

  A stone is thrown straight up. At the top of its path, the net fo1 w x 5yh/(hrkib2 l(dura.l dice2b2(rce acting on 5y((2.1ialbir2h2bk d rx dc /(wl uheit is

  A 20-N weight and a 5.0-N weight are 1lpw1k q ;1fjzle7/v1gmdi )idropped simultaneously from the same height. Ignore air resij;e 1vg f/lwpi1qml1)i z dk71stance. Compare their accelerations.

  A brick and a feather fall to the earth at their respective terminal 7smf)x7.ajqb j+6 no0igoum1velocities. Which objo)oig f0m7m.j bq 1as+6 xu7nject experiences the greater force of air friction?

  An object of mass m is dw) q/t pz4b*qhanging by a string from the ceiling of an elevator. The elevator is mot4/p * )wdzqqbving up at constant speed. What is the tension in the string?

  An object of mass m is hanging by a string from the ceilg2uhr*s 3)iezing of an elevator. The elevator is moving upward, but slowing down. Wha2eg i3hs *urz)t is the tension in the string?

  The force that keeps you from sliding on an icy s8/bvff:o p tzrv f9b6-idewalk is

  It's more difficult to start moving a qc46+ww2*i n tx 6 sru/xfgq8gheavy carton from rest than it is to keep pushing it with constant velocityqc/n6 g2 *i 8rw6+guq4 xwsfxt, because

  A horizontal force accelerates a box from rest across a hopc9b:aobdjj 9mb/*;)fdukl vk- - r0l rizontal surface (friction ijlbacv ;u0:mblkr-*) d/do 9k-9 pbjfs present) at a constant rate. The experiment is repeated, and all conditions remain the same with the exception that the horizontal force is doubled. What happens to the box's acceleration?

  A packing crate slides down an inclined ramp at constant velocity. Thap;yhd:mjycx 2: zo) 8us we can ded :xh)p2dy8m ajzy: o;cuce that

  A block of mass M slides down a frict9a-8x7mol -utn0 -k;t ofyo cdionless plane inclined at an angle q with the horizontal. The normal reaction force exerted by the plane on the block 9-f 87d;ko oxylm-untoc t-a0is

  A block of mass M slides down a f6j 2 x+j9:djfb7uojt 5-bga wrrictionless plane inclined at an angle q with the horizontal. The normal reaction force exertedgjr:-o + a x2jbbjwtuj 756f9d by the plane on the block is directed

  A block of mass M slides down a frictionless plane inclined as r .fw93wv(4t cd/no,mp v6out an angle q with the horizontal. The gravitational force is direcwuv, v4/ w9d sr6. (cftonomp3ted

  Two toy cars (16 kg and 2.0 kg) are rg+e n)s (ifh(9il0 4m6eeqga beleased simultaneously on an inclined plane that makes an angle of 30e with the horizontal. Make a statement which best d9g +6(0be gaelh(qn4s mf)iieescribes their acceleration after being released.

  An object sits on a frictionless surface. A 16-N force is applied to thelgg(pz (0: dslpa(f.rwx6igjy 75 vs* object, and iw*lzarl.yj:s 06vg(g57d (pp ( gfixs t accelerates 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 7.0 )g8p pvgv-x xszi)a;1 s. What is the average forward force on the x gspia xg z))p;v-18vcar?

  Starting from rest, a 4.0-kg body reaches a speed of 8.0 m/s v)+hq 5lz(s 8ulid3swin 2.0 s. What is the net force acting odz8l)sq5ls(vhi3 +wu n the body?

  An antitank weapon fires a 3.00-kg rocket which acquires a speed of 50.0mbr8ej*:2drx m/s after tra*:8mrbd2jxre veling
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 mass from r g7x. c;rzhp:fe .r7;p :xhgczfst,

  What is the mass of a person who weighs 11sa tcuf.fp.*e3o1 ec ,l px1*p0 lb?

  What is the mass of an object that weighs 57 )rheottk4 gr;rs n2250 N on the surface of the Earth where the accelen2rs r4g57ot hk )etr;ration due to gravity is $9.80 \; m/s^2$?

  An object has a mass of 60 kg on the Eqy3ein -pl( s)0nst;carth. What is the mass of the object on the surfysn iq npl e(-3;0cs)tace 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 Moon. T/ ,ol y-qkxewyt:.af :aug+mu8 6 nid+he Moon's gravity is one sixth of Earth's. Co+ t /-uyux6f.g ewlon,km i:qdy8 :aa+mpare the masses of the objects.

  Sue and Sean are having a tu p-8ngcqv+ oi/g-of-war by pulling on opposite ends of a 5.0-kg rope. Sue pulls with a 1poi-cn+v q/8g5-N force. What is Sean's force if the rope accelerates toward Sue at $2.0 \; m/s^2$?

  A stack of books rests on a level frictionless surfa y/bx8 g bavfs+pzmw);1 7rek*1t4l dace. A force F acts on the sty* 7b4 /;eavlbmaf tsrkzg d)8x1w+1 pack, and it accelerates 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 an5r7lnu5 ve j7orrgk.3 elevator. What will the scale be reading when the elevator is acc55lrjrr3ne.uvgk7 o 7elerating downward at $4.00 \; m/s^2$?

  A person on a scale rides in an elqx-, *boaji /fka w80mar0l,kevator. If the mass of the person is 60.0 kg and the elevat, -awxk0,a8 m liabqjr/* f0okor accelerates downward with an acceleration of $4.90 \; m/s^2$, what is the reading on the scale?

  A person on a scale rides in an elevator. If the mass of the pert /ctl (29sk6pwpt27kb opj2u son is 60.0 kg and the elevator accelerates ujp2/wc 2k29 s p7(tutobk ltp6pward with an acceleration of $4.90 \; m/s^2$, what is the reading on the scale?

  Two horizontal forces act on a 5.0-k:ba idsxrd9 z//rmiox.8z+5 tg mass. One force has a magnitude of 8.0 N and is directed dz+rzd 5x s9 b r:o/8ixiadm./tue north. The second force toward the east has a magnitude of 6.0 N. What is the acceleration of the mass?

  An object of mass 6000 kg rests on the fl72ydg a mah);dffr y3,atbed of a truck. It is held in place by metal brackets that canyd;,)2m raadyhf f37g exert a maximum horizontal force of 9000 N. 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 4efsf6r9jd +x 1fr+xv flatbed of a truck. It is held in place by metal brackets that can exert a maximum horizontal force of 9000 Nx9s xevrrdj ff+41f 6+. 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 = 0.60 kg and m = 0.4ri8 wu: dlliu9(xtj2v l,3:d l0 kg, what is the magnitude of the accelel l 8 trdluu3:wlxd,j(i 2i9v:ration of the system? (Ignore friction and the mass of the pulley.)

  In the Atwood machine shown in2/a / dar ;w5b9fq;sclfy1eyj Fig. 4-1, if M = 0.60 kg and m = 0.40 kg, what is the tension in the string? (Ignore friction and the mass of the pull;e/bf2;a 59dwycr 1jqy/a flsey.)

  A student pulls a box of books on a smooth hor )n 4a2x nccwhgi9ipf 7c5v 80r(4q c0dqz0xbkizontal floor with a force of 100 iqa4dgc 205nrxvf89c4 z7bwi0 ()0n q cckxphN in a direction of $37^{\circ}$ 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 smooth horizontal floor with a forc 9tf ey- ivkhreowbz:xz.dv)985/mt +e of 100 N in a direction of 37.0e above the horizontal. If the mass of the box and the books is 40./99v-+ ed)xmerzv5i8 kh bwtof :.zty0 kg, what is the normal force on the box?

  A traffic light of weight 100 N is supported by two ropes a**4j.w csmi ;la9avde*9cj fe s shown in Fig. 4-2. What arejm *9* 4leas.jwe;cav*cid 9f the tensions in the ropes?

  In Fig. 4-2, if the tensions in the ropes are 50 N, what is the mascey1yu1 t4g(l ruv3vw4w2yxu3:; pqd-n ml8ms of the traffic light?w1m1v t 4uc-rup2 8 lyv 3gx3n(;qdm:4yly uwe

  Two boxes of masses m and 2m are in contact with each other on a f6 sy1) oqqbrm-rictionless surface. (See Fig. 4-3.) What is the acceleration of the more massive bo1bsqm -oq6)ryx?

  Two boxes of masses m and 2m are in contact with each other on a frictiff(ubv4-pa wl4ht)k yi8;u- (kip(gw onless surface. (See Fig. 4-3.) What isahuu-(;) kfv k(( y-g4b l84tpwiip wf the net force on the more massive box?

  Two boxes of masses m and 2m are connected by a rope. xu +t7o;j(m fu(See Fig. 4-4.) If the forward force on the more massive box is F, what is the tension in t u7 ;xomu(+jfthe connecting rope?

  Two boxes of masses m and 2m are connected by a rope. (See Fig. 4-4.) If the m 4k/tqncyxz i( kk64j3e+6 pgforward force on the p tk/zkgqkjn644i(e3 m xc 6y+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 in )xm(pu 8bgrw+Fig. 4-5. Box I of u)w(mrgbp8x+ mass
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 frictions between a 3.lw1+k )l:jgg8 lz n-bs0-kg box and a desk are 0.40 and 0.30, respectively. What is the net force olkgg znl-b+8 ws1)l :jn the box when a 15 N horizontal force is applied to the box?

  The coefficients of stai-w nwq,bh 64etic and kinetic frictions for plastic on wood are 0.50 and 0.40 ,q-eiwwhb n46,
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 direction. It slows and com79pdnk.. , v ctvey7xmes to a x79k., ny vcmtpev 7.dstop with a constant 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 horizontal surface is pulleddp9+.8m 4 h chjt8sziy by a 5.0-N force. A 3.0-N friction force retards the motion. What is the acceleration o tjm88+cdy4zhsi.p 9h f the object?

  A horizontal force of 5.0 N acceler kehdm mc 6yq5v.m;9:oates a 4.0-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 pv:m1c ui)/i0(zu wce. It slides 50 m on the ice before it stops. What is t:i (wpuium/) 0 c1zcevhe coefficient of kinetic friction between the puck and the ice?

  During the investigatg7gje 5m9kcch2n 9u(k ion of a traffic accident, police find skid marks 90.0 m long. They determine tguceck (9hm 5 2jnk7g9he coefficient 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 stacked. (See Fig. 4-6.) The s3:pu/8k c ys5u-q4dx ssq;1zj:puyvlurface 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 slide on the more massive box, what is the static fyudy ;1s:3x psp48qq5zj:/l-uc uvksriction force on the less massive box?

  Two boxes of masses m and 3m are stacked. (See Fig. 4-6.) .2kg zxczm5:me5mp*6ow .4i mpp2uu kThe surface between the more massive box and the horizontal surface is smooth and thx*imzp e ku 24upp mmgzw65okm..5:2ce 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. 1x(;vk z gl(uhug:,2bzy 2dsnThe plane is inclined at an angle ofg b ((nsz xduh;,kz g2vu2:1ly $30^{\circ}$ with the horizontal. What is the object's acceleration?

  A 10-kg mass slides dovubl3d mf -i.e,7ge/a;, ldwown a flat hill that makes 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 a smooth inclined plant k3 tusby,2e 5vn40axe 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 inclinc5 s8ny4hmnb- ed plane tilted 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 const52luddqtn .w 2ant velocity of 6.0 m/s.u2.d dnq wl25t
What is the coefficient of kinetic friction, if the plane makes an angle of $25^{\circ}$ with the horizontal?

  An object with a mass m9krlkql j50s2a +on9yxg 8uh3bot3 ,w slides 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 slide*+m 8uj pld2xms 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 weighou -)+e- 54fowss ngjzing 500 N along a rough surface. The cable attached to the log makes an angl4 -w -n5ezsg)osjuo+ fe 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 plagish2q+0kz(fn b2u19 u kh7m tne tilted at an angle of qgz9hbi(02ut2s +kmhf17knu $33.5^{\circ}$ 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 incline is gradually inq.ui osiu 3oqqs8z:9 0creased until the object begins to slide. The 0.oq: squ98 3izoqisu angle at which this occurs is q. What is the coefficient of static friction between the object and the plane?