Which of Newton's laws best explains5,9 rrk),vy f;aieabi why motorists should buckle-up?

  When you sit on a chair, the resubot84up s; 2keev47mfjf/mf ,f/j)g ultant force on you is

  In the absence of an external force, a moving object w z 1)s4mc oc9uy4,qdmjill

  When the rocket engines on the starship NO-PAIN-NO-GAIN are suddenly turneds4o-mx5 b;1xixe6 wgn off, while travelinx65woe xx41n-;sim bgg in empty space, the starship will

  A rocket moves through empty space in a straight line with constant speed. nbdhz)r7rmf46:a cv 0It is far from the gravitational effect of any star ornbrha4f 0:z mcd6r)v7 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, andb su-18 tvjy8c you suddenly fall forward. You can imply from this that the bus'vucjb s8y-18t s

  You are standing in a moving bus, facing forward, anz.c76 vv(v wxok m.cr*d you suddenly fall forward as the bus *m(vv vw c7.czok 6rx.comes to an immediate stop. What force caused you to fall forward?

  A constant net force acts on an object. Describgl(4c.cvix4 5i zcfl 0e the motion of the object.

  The acceleration of an object is inversely prvt,xaksfp+o, -y :d+lw9i,jxoportional to

  A net force F accelerates a mass m with an acceleration 1k:r7;g l. stc kodbad)lx-)ya. If the same net force is ). sto y:7rkc a)l -db1kgx;ldapplied to mass 2m, then the acceleration will be

  A net force F acts on a mass m and produces an acceleration a. What dca 9d6(g pk;zacceleration results if a net force 2F acts on mad 6cz9agdk(p; ss 4m?

  If you blow up a balloon, and then release it, the balloonu-.s8ctxw37bqre t j6m c a.;o will fly away. This is a8tc3wx7.c; be oqsra.j tu6- mn illustration of

  Two cars collide head-on. At every moment during the collision, the magnitude p;qlc,pkwb k)33p.yp ,p.iu bof the force the first car exerts on the second is exactly equal to the magnitude of the force the secon; kkcp qpiupw),y.b3lp b3p, .d car exerts on the first. This is an example of

  If you exert a force F on an object, the force which the object exerts ondm cq2cllc.:.qz tl,9 you will.2d tlzlqcl,qc: c 9m.

  Action-reaction forcesh 52y2r*s 8rkn+vn f/6iqrlqd

  Action-reaction forc uqxs z6tkt 7+-cpjlx e.-c0k1es are

  A 20-ton truck collides with a 1500-lb car and .1vo:fi9p8 xbcez kh+causes a lot of damage to the car. Since a lot of damage is deif+9:z p1bcxo.8 kv hone on the car

  An object of mass m sits on a flat table. The Eatr 8tv4;n m8pqrth pulls on this object with force m;8 rmvtn4tp8qg, which we will call the action force. What is the reaction force?

  A child's toy is suspended from the ceiling by means of a string. o(a tf9nr:j ,vzf: 3boThe Earth pulls downward on the toy with its weight force of 8.0 N. If this is the "action force," what is the "reactio:r,n9bfz f3jota (vo :n force"?

  Your bat hits the ball pitched to you with a 1500-N instantaneous for o.zug+qohkk:j xm. ka4y*4 -pce. The ball hits the bat with an instantaneous force .kuj :4pq.g+ oam xkokyhz*4-, whose magnitude is

State Newton's threes/ 9 6pvy.pl/3yer8lwdvh.hj laws.

  Mass and weight

  The acceleration due to gravity is lower on the Moon than on 1/e7 zf0vybylEarth. Which of the following is 7vy0l/yfez1b true about the mass and weight of an astronaut on the Moon's surface, compared to Earth?

  An example of a force which acts av)7eau - zd(qst a distance is

  Who has a greater weight to mass ratio, a person weighing 400-o)*ou9sg jff N or a person weighing-ujfg 9os)f*o 600 N?

  A stone is thrown straight up. At the top of its path, the net force acting onyhztsu jf-;/4 it is- s ftju;/y4zh

  A 20-N weight and a 5.0-N weight are dropped simultaneously from he1 qwd3)t8g-e1 esjnthe same height. Ignore air re e h-edstn11qg )3wje8sistance. Compare their accelerations.

  A brick and a feather fall to the earth azbv /g-pyw y 8xn)e:4lt their respective terminal velocities. Which object experiences the greater force of air friction?gl)n pxe8y4z/ b-vy:w

  An object of mass m is hanging by a string from the ceiling of an hxd ftp+26ts 6elevator. The elevator is moving up at constant speed. What is the tension in the stf6tt 62xh+spdring?

  An object of mass m is hanging by a string from the ceilindw/l7 q xdjl)+u1lpi:g of an elevator. The elevator is moving upward, but slowing down. What is the tenld 1duqil)l p /+:jx7wsion in the string?

  The force that keeps you from sliding olvjqz *pn a8/3g ukg 5o,;alz-n an icy sidewalk is

  It's more difficult to start moving a heavy carth7u -afy25s-u ehr (pgon from rest than it is to keep pushing it with constant velocity, aep h-5-s2fg 7uhyru(because

  A horizontal force accelerates a box from rest across a horizontal5ygy4j- mk hw jl7qs /f;9hmzb44qpp5 surface (friction is 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 happezqp5-w4;jqyj /p7hl y 4 k smhbf495mgns to the box's acceleration?

  A packing crate slide: r 3nt rzi5/lxz(zq6rq8 0shms down an inclined ramp at constant velocity. Thus we can m8sn zi0 rx5 zr3rzq:(t6/qhldeduce that

  A block of mass M slides d4 k3fs.+enc kvqy -g)uown a frictionless plane inclined at an angle q with the horizontal. The normal reaction force exerted by the p ykfv34gc)k e .-+squnlane on the block is

  A block of mass M slides down a frictionless plane inclined at an anglts:u,c+ cgtjl ou*o0 5e q with the horizontal. The normal reaction for+5:g ,*lsoc tujct 0uoce exerted by the plane on the block is directed

  A block of mass M slides down a frg)b (izk u).sw( hwwg)ictionless plane inclined at an angle q with the horizo g)z( w.k)ugw(h ibs)wntal. The gravitational force is directed

  Two toy cars (16 kg and 2.0i8dai h)iy..b 13jua)bkb 7xv kg) are released simultaneously on an inclined plane that makes an angle of 30e with the horizontal. Make a statement wh 1 7yui8dx bb ihvkj))3ai..abich best describes their acceleration after being released.

  An object sits on a frictionless surface. 7kik.q,((l1ffgz sm iqx+pb o495i mq A 16-N force is applied to the object, and it a +1k .,7mxiq4qisbo9k5f l( fmgqpiz(ccelerates 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 2m*y uf :r dpy0had(a0qco4:fx-h +lzm/s in 7.0 s. What is the aveuf :dmlqh-ao a+(cyr0 2:fydzh4 0px*rage forward force on the car?

  Starting from rest, huaq93msr9s; : 67 gj,q vd (ovmuhnl)a 4.0-kg body reaches a speed of 8.0 m/s in 2.0 s. What is the net fo3sd ,q7(a)l gnvsjrovhum;:uh 99 6qm rce acting on the body?

  An antitank weapon fires a 3.00-kg ;efdf a vck6db,;ld;;rocket which acquires a speed of 50.0 m/s after dff ;kbed;;d la6;,vctraveling
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 0 f;yd: bdo8umpush a 10-kg mass from rest,df:bdy8 om; 0u

  What is the mass of a person wh8bfhtv d*( 5yao weighs 110 lb?

  What is the mass of an object that weighs 250 N on the surface of th pghg6 eor;*)yi ojln/jyia(5) p5zf0 e Earth where the acceleration due to grav zige p0/65o)lhgr*n ) p5o(jyyjaf i;ity is $9.80 \; m/s^2$?

  An object has a mass of 60 kg o h7rd/e w vc.9 0gvdz5rgj*yh/n the Earth. What is the mass of the object on the surface of./ j hrgd wvvzgchry/07 9de*5 the Moon where the acceleration due to gravity is only 1/6 of that on the Earth?

  Object A weighs 40 N on c l w9x+b og1kqf:hbv2.+d,i hEarth, and object B weighs 40 N on the Moon. The Moon's gravity is one sixth of Earth's. Compare the masses of the oh2ld 9khx+vfwi+1oqgc b:b., bjects.

  Sue and Sean are havin:m dn gkk620t8v3nvmz g a tug-of-war by pulling on opposite ends of a 5.0-kg rope. Sue pulls with a 15-N force. What is Sean's force if the rope accelerates toward Svnnkd m kz0t8mv 26:g3ue at $2.0 \; m/s^2$?

  A stack of books rests on a9 t0e2xmfi xn9 k(rva( level frictionless surface. A force F acts on the stace(9 ritx f0k(29v maxnk, 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 anv eb hr1 agj4 o,ar+ijp.v8ige47tg)7 elevator. What will the scale be reading when the elevator is accelerating downward at + hgvr4 )ea.ag8 pt jje,1irvi747 obg$4.00 \; m/s^2$?

  A person on a scale rides in an elevator. If the mass of the person a *b 0da61r*s5gvxo nois 60.0 kg and the elevator accelerates 1x ngbaoos60*dra*v 5 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 persppy: 9y(ekz+lux +: hxon is 60.0 kg and the elevator accelerates upward with plu+h: xky 9zx(pey+: an acceleration of $4.90 \; m/s^2$, what is the reading on the scale?

  Two horizontal forces act on a 5.0-kg mass. One force has a magnitude of 8.0 N epwf*csg i h7iv2g,w m.bz2o2n,;3jdand is directed due north. The second force toward the east hasw oz, 2g isv227fjwc3gbh,d;pe*mi n. a magnitude of 6.0 N. What is the acceleration of the mass?

  An object of mass 600ntlev*dn(q k.up*.3rn: l l4e0 kg rests on the flatbed of a truck. It is held in place by metal brackets that can exert a maximum horizontal force of 9000 N. When the truck is traveling 15 m/s, what is the minimum stopping distance if the lok*v3. .en*elt: d( lpunlq4nrad is not to slide forward into the cab?

  An object of mass 600:bg c (dhurq).62ez knsf /8hv b+zrf:0 kg rests on the flatbed of a truck. It is held in place by metal brackets that can exert a maximum horizontal fo.e:uzfbc ( 8qzhdfrsv/+b knr:gh6 )2rce 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 = 0.60 kg an*zit)j)zjml ;o5r0yg05uh t cd m = 0.40 kg, what is the magnitude of the acceleration of the system? zi lj5;utym0th) *zc5) 0gjro (Ignore friction and the mass of the pulley.)

  In the Atwood machine shown in Fig. 4-1, if M = 0.60 kg and m = m q835 ;blbiie2co-vqj: ri ,8t jxnqdt(4l4s 0.40 kg, what is th(l iisne i-jtl5ot4 bcqbm,2x3rq 4; 8:qj8vde tension in the string? (Ignore friction and the mass of the pulley.)

  A student pulls a box of books on avd-kg23g o31c,jg mqq-x e be4 smooth horizontal floor with a force of 100 N in ao 4,mjgd1ce-3e3 kvbgxgq-q2 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 horizonty,udd syg+ .4 augba(g67cc8fal floor with a force of 100 N in a direction of 37g7g 8cyaygs,bad d4c.(uf +u6.0e above the horizontal. If the mass 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 sh(n0x vcexv(0me34jtr8+wpxn e fp) .sown in Fig. 4-2. What are the tenesj4 w00+f n(emp vnx)8e3xrtc p .xv(sions in the ropes?

  In Fig. 4-2, if the tensions in ty vji7 g m:4jep,grj165v7rd ahe ropes are 50 N, what is the mass of the traffic lig6ejr 4,ji1m:yv7 7agd j5rp vght?

  Two boxes of masses m and 2m are in contact with each other on a frictionlepiz2cmq* f-- vss surface. (See Fig. 4-3.) What is the acceleration of the more ma-ipc*v q2zmf -ssive box?

  Two boxes of masses m and 2m are iweda *q2ka*rgm5h 9epkf(cj u/d-z:,n contact with each other on a frictionless surface. (See Fig. 4-3.) What is the net force on the more mc*dg emf9k-5/aedw(h2 qap* j, zru:kassive box?

  Two boxes of masses m and 2m are ctg r*ly/xppe 9wzi4d r1-y;i, onnected by a rope. (See Fig. 4-4.) If the forward force on the more massive box is F, what is the tension in the c- 1idzry 4e pip9x;/rgl wty,*onnecting rope?

  Two boxes of masses m and 2m are connected by a 2vzjze .6cathz8a fl 91z*ivr, v5 cq)rope. (See Fig. 4-4.) If the forward force on the more massive box is F, what is the accelerati.rz8vfvzzh5i,te)*z9a1cva6 lj qc2 on of the less massive box?

Two boxes are connected by a cord running over a pulleym2y8avl z0o. r as shown in Fig. 4-5. Box I ofva82zomyr0 l . 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 frict*fpk5 ep(f/ 9dax8 uftions between a 3.0-kg box and a desk are 0.40 and d5kpxup8* fafe9 /f(t 0.30, respectively. What is the net force on the box when a 15 N horizontal force is applied to the box?

  The coefficients of static-s 0bqqc2d sh/ and kinetic frictions for plastic on wood are 0.50 and 0.qs /-0bh2qcsd40,
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 direwe0;firfb, e sz/jh7+ ction. It slows and comes to a stop ;zbefwi0,+jef / r 7shwith 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 pulled vv- ,;yq u7xt5:jw (umg0di hvby a 5.0-N force. A 3.0-N friction force retards the motion. What is the acceleration of the (d,v 0;7u5xqgywm j:vtvi - uhobject?

  A horizontal force ofj. z9kzg*6pfkzc8 - r l(;yuod 5.0 N accelerates 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. It slidebl3tp-ykw ;6is 50 m on the ice before it stops. What is the coefficient of kinetic friction between the puck and i l3kt6-pw;yb the ice?

  During the investigation of a traffic accident, police find skid marks 90.qh5tkgt k*,.: v:n : p(k9ysp r+zktdh0 m long. They determine the coefficient of friction between the car's tires and thehgq*dkkty rz5v tk9,+:( :hp n:.tpks 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. zy.7p htp/3rr (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 slide on the more massive box, what is the static frictiont 3r.prz7h /py force on the less massive box?

  Two boxes of masses m and 3m are stacked. (See Fig. 4-6.) Th-x+ohnrn* yvj cbk7; :e surface between the more massive box and the horizontal surface is smooth and the surface betweenv*xo j+ nc:rhk -;y7bn 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 fricduzbmu 0zfl la+rv*i;.94p7 ctionless inclined plane. The plane is inclined at an angle of dzf70bu* v .z4 r; lilp9uamc+$30^{\circ}$ with the horizontal. What is the object's acceleration?

  A 10-kg mass slides down: qgm ka,w/zz/ 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 plane with an anglr6 h(a4 ik-fa.oscab -e 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 tilted at an angl1 m3 bf9z .-uprmdb58k2n0 jus/lokiue 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 cogc; ahyzrt,e o 16qea8 +v3o4wnstant velocity of 6.0+o oate,zyr4 1gqc ;86he3 avw 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 slides down a1wm,xa:g6yeo1b rkk u bzum7z fd4+ v)ab11o: 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 slides down a rym680puw* y e+hjl9sd ough $37^{\circ}$ 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. T1n ll;hv0igl;ddn rpi 5n3n0u w565jr he cable attached to nl3vhdpjignr;w55 ;1nild l0nu5 0r6the log makes 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 roz9:tyofn5ska(upm 0 h z09s 0ap.e 6raugh inclined plane tilted at an angle az9se0sf 00kh9t5apypzu(a no 6r:m. of $33.5^{\circ}$ 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 incli +u-j 1/onrnygned plane. The angle of incline is gradually increased until the object begins to slide. The angle at which this occurs is q. What is the coefficient of static friction between the object and th1 n- g+nor/jyue plane?