Which of Newton's laws best explains why mon11c f sm/itm+-oba- li)tj(u- zuh3otorists should buckle-up?

  When you sit on a chairf04lnweo(*rb: *xa3c 1avrwb, the resultant force on you is

  In the absence of an external force, a movin wy at.4rd/)i- q0phstg object will

  When the rocket engines on the starshu+qvejt*f 8m svq t:3:ip NO-PAIN-NO-GAIN are suddenly turned off, while traveling in empty space, the starshipv8tq :j+uq tm3fves :* will

  A rocket moves through e h,z*sp0p 6rhympty space in a straight line with constant speed. It is far from the gravitational effect of any star or py,p0h6sh rp*zlanet. 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,w, edx00hlj8eadn0 ip::lrmfwx 1e83 facing forward, and you suddenly fall forward. Y:x3:8,0r01lwdfjnp xh w8 0dee leaimou can imply from this that the bus's

  You are standing in a moving bus, fac5q3ez(k bwb i;ing forward, and you suddenly fall forward as the bus ebwi5(;z3q b kcomes to an immediate stop. What force caused you to fall forward?

  A constant net force acts jk. rjop6 wl.e es5tn0)v p4-bon an object. Describe the motion of the object.

  The acceleration of an object is inversely proportion.hkov9qvy l(g6 r0*. nfczti/al to

  A net force F accelerates a mass m witsavs+1,*r ,zizyyiq3 h an acceleration a. If the same net force is applied to mass 2m, then the accelerati zq*zsiv, i ayys1,+3ron will be

  A net force F acts on a mass m and produces ( c .mj;hfx,a5hfj7tyan acceleration a. What acceleratio fy7a5fjhm.hc(,jxt;n results if a net force 2F acts on mass 4m?

  If you blow up a balloon, and then rent fjd e(*sd;2(pv j,wlease it, the balloon will fly away. This is an ilp,*( f n(j;jv2dtsew dlustration of

  Two cars collide head-on. At every moment during the -qcvumg 8bd .z d23r0tcollision, the magnitude of the force the first car exerts on the second is exactly equal to the magnitude of the force the sq2.0v 38gbzmt cur-ddecond 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 on you b a3pe7-n5ghzf2uq)b wi2h3-pb)eqbf unzg a 57ll

  Action-reaction forcebk57 efv/btvpvjg ,yt0kv29) 2- a jums

  Action-reaction forces repvh6 x 90f.utv82di-e bmk;.2lxg c are

  A 20-ton truck collides witz2urmpe 397 7wljz d4eeuv:g3-arzm8 h a 1500-lb car and causes a lot of damage to the car. Since a lot of d z:8eu7d9u3w4mg z l2 3z jme-7revarpamage is done on the car

  An object of mass m sits on a flat table. The Earth pulls on this obn:39 emqg+f5ecdr 4cbject with force mg, which cer 4d+:nc9 bfm gq53ewe will call the action force. What is the reaction force?

  A child's toy is suspended from the ceilijr* hs/ -5fuvs0u:u 4wrmaim+ng by means of a string. The Earth pulls downward on the toy with its weight force of 8.0 N. If this is the "action force," whatwirr 4mu uj*5+-afvs:0h /smu is the "reaction force"?

  Your bat hits the ball pitched to you with a 1500-N instantaneous force. Theegq,1hy5 pd xx nvdk8:(xo.z4 ball hits the bat with an instantakqxog dh :, pe1.(vx x54n8ydzneous force, whose magnitude is

State Newton's three lap4jf+ew fa()//njjspy:)b ruws.

  Mass and weight

  The acceleration due to gravity is lower on the Moon than on Earth. Whics4wdljsp4q-x e*, j h3h of the following i 4xj-3p4,ws *esjdq lhs true about the mass and weight of an astronaut on the Moon's surface, compared to Earth?

  An example of a force which acts at a distance isc9/ j86yaz ot roktn) xaz:y/*

  Who has a greater weight to mass gq+g ds,7mo lcr)48ajratio, a person weighing 400 N or a person weighing 64a 7l,j 8cms dgg)+qor00 N?

  A stone is thrown straight up. At the top of its path, the net force acting o0(m+u*:0itu a nzd:aul 1n tlon it is:olt0u(du* 0 +at minz:la un1

  A 20-N weight and a 5.0-N weie;r4duo, 3 avuu hoeo4( xv.3tght are dropped simultaneously from the same height. Ignore air resistance. Compare their acce4 (u3h .reuo43uv etx;d,oov alerations.

  A brick and a feather fall to the earth at their +9 +il6 hzflxbq-z0g 9fjfe5rrespective terminal velocities. Which object experiences the gzfzflb9 ielf9g jx0q 6r5-+ +hreater force of air friction?

  An object of mass m is hanging by a string from the ceiling oj2nm+-e x df aop g0b)lu4o8j++9fkoof an elevator. The elevator is moving up at constant speed. What is the tension in the sto8o+ lon-j embu+ox40 dkp2j9gf a+f) ring?

  An object of mass m is hanging by a string from the ceili*m*zwth q.la ;zm3-qd, qvs-kng of an elevator. The elevator is movik* *zqmhmw3-d qza;t,l-q sv.ng upward, but slowing down. What is the tension in the string?

  The force that keeps you from sliding on an icy s*pssn8cke6p 9 rw:,1; +zkdlm4bccs k-nfwo(idewalk is

  It's more difficult to start moving a heavy t3/v8j xwa 33s,bjap3trca6(jt:tz i carton from rest than it is to keep pushing it with constant vepjjat3z86,ta v3i(:3cbasx t3 /j tw rlocity, because

  A horizontal force accelerates a box from rest across a horizontal shv / 1fuq wf 0zv5kz f20hv5o+p7awdp0urface (friction is present) at a constant rate. The experiment is repeated, and all conditions remain the same with the ex75/ kzd+2avfwzv hpfpvf h0w 1uo5 00qception that the horizontal force is doubled. What happens to the box's acceleration?

  A packing crate slidj;:.srj-fqie4 c4kj3w 5w kkoes down an inclined ramp at constant velocity. Thus we can deduce twrw5.k s4foi: c q4ekkjjj ;3-hat

  A block of mass M slides down a frictionless plane inc;n. q7 pcfn8jilined at an angle q with the horizontal. The normal reaction force exerted by the plane on jip7. fnn8;cq the block is

  A block of mass M slides down a frictionless plane inclined at an84odqgy wu7 oz1.rn m2 angle q with the horizontal. The normal reaction force exerted by the plane on the block is di o2qw.u 8z1gom7 4rnydrected

  A block of mass M slides down a frictionless plane inclined at an angle q wi 0ha)/qjjci9 1yqdp llch25d-th the horizontal. The gravitational force is d5 qd ipyjc1jh- h/l0 9acd)2qlirected

  Two toy cars (16 kg and 2.0 kg) are released simultaneo -x peo5mt 4tj9xi4+bhusly on an inclined plane that makes an angle of 30e with the horizontal. Make a statement which best describes their acceheox m5b9j p+xtt4-i 4leration after being released.

  An object sits on a frictionless surface. A 16-N force is applied to the obr :i p*e r48ps4nhka.xject, and it ai*nr s8:h e p4.p4karxccelerates 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 f / rkqut u:ke47ee).min 7.0 s. What i)r. kt eukm:uq fee47/s the average forward force on the car?

  Starting from rest, a 4.0-kg body reaches a speed o4gsv i:vof7mx 3n r fxi;fm26.f 8.0 m/s in 2.0 s. What is the nrx 36 vs4 nimvmox;72: gfffi.et force acting on the body?

  An antitank weapon fires a 3.00-kg rocket whic(y-lzoo0ds e4am-2 dl8n*gj lh acquires a speed of 50.0 m/s after travo0s84md*-- 2 l ( llandgyzejoeling
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 witht50x kv/nobd- the same force that you push a 10-kg mass from retnkdx b-0o/5vst,

  What is the mass of atyh7 kyx6ff.5i7:po ga0lk ;b person who weighs 110 lb?

  What is the mass of an object that weighs 2ttsu*bzq j /0(50 N on the surface of the Earth where the acceleration due tozqj0b tu/ts* ( gravity is $9.80 \; m/s^2$?

  An object has a mass of 60 kg on the Eatdcz jy5r, (n7v:)vyqrth. What is the mass of the object on the surface of the Moon where the acceleration y(vz ,) qctvd:yj 7rn5due to gravity is only 1/6 of that on the Earth?

  Object A weighs 40 N on Earth, and obje ag 1xmaj98z7ja;cc0r ct B weighs 40 N on the Moon. The Moon's gravity is one sixth of Earth's. Compare the masses of the ; 1jxr879jmcz a0aacg objects.

  Sue and Sean are having a ipx-hjit,xw .z r+ /n2l oz5z(tug-of-war by pulling on opposite ends of a 5.0-kg rope. Sue pulls with a 15-N force. What i(hp.- o/z,xr52 +nzizjit wxls Sean's force if the rope accelerates toward Sue at $2.0 \; m/s^2$?

  A stack of books rests on a level frictionless surfam;cwv+ y/nm7 pce. A force F acts on the stack, and it accelerates at 7+nv m;w/mypc$3.0 \; m/s^2$. 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 stq7qwv g0+e )ls;/puzrands on a scale in an elevator. What will the scale be reading when te)s0 g;l7q rqwvu/ zp+he elevator is accelerating downward at $4.00 \; m/s^2$?

  A person on a scale rides in an elevator. If the mass ofau mn2;;h;jax the person is 60.0 kg and the elevator accelj2a h;x am;;unerates 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 person is 60.1 /+pixde:el t0 kg and the elevator ac tl1ipedxe/+ :celerates upward with 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 haz3 l,q.v jb*eea5-btz s a magnitude of 8.0 N and is3 vt-qjba5*b.ee l,zz directed due 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 rests1r5vtkj8 nl y pz4g sao);4wr5 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 load is not to slide forward into the cabpntzy;rkrg51j8ovsa4 ) 5l 4w ?

  An object of mass 6000 kg rests on the flatbed of a trud nb 7fg qs-jr.bnk) ,p5z3.7tfl8pxl ck. It is held in place by metal brackets that can exert a maximum horizontal forn -z77 bpj .bkn 5sl3rdlfx8g,fp )qt.ce 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 =hm/2+1j1-wxynu /h cdy fx5zj 0.60 kg and m = 0.40 kg, what is the magnitude of the acceleration of the system? (Ignore friction andn2115cyyx/ dh zmjjxh-u +/ wf the mass of the pulley.)

  In the Atwood machine shown in Fig. 4-1, if M = 0.60 kg and m = 0.40 kg muzs u8rd/xe:x2 w(6w, what is the tension in the string? (Ignore friction and the mwrux 26e(x u/8wds z:mass of the pulley.)

  A student pulls a box of books on a smooth hor13s6sw jzd t4rizontal floor with a force of 100 N i6 14wsst z3rjdn 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 hor.em0ecwr;f+6qs, w ogizontal floor with a force of 100 N in a direction of 37.0e above the horizontal. If the mass of the box and the books is 40.0 kg, what is the f0ow6 s,eg;qr+cw me.normal force on the box?

  A traffic light of weight 100 N is+;e ; acxft 0t z5meb87szu0gs supported by two ropes as shown in Fig. 4-2. What are ;tx;ec +u7zs08sg5e0b f mzat the tensions in the ropes?

  In Fig. 4-2, if the tensions in(4 nipr-zkkblm:: 9v l the ropes are 50 N, what is the mass of the traffic 4b l(rn: l-k:izmv9k plight?

  Two boxes of masses m/f u8n:9jbib4ifzw;n and 2m are in contact with each other on a frictionless surface. (See Fig. 4-3.) What iz;if uf bwbn94/ jn8:is the acceleration of the more massive box?

  Two boxes of masses m and 2m are in contact with each other cu ew3.zwjhe7(q)fw,s c 2cg5on a frictionless surface. (See Fig. 4-3.) What is the net fwew2qshj .ec 7),f(wcug 3z c5orce on the more massive box?

  Two boxes of masses m and 2m are connected by a rope. (See Fig. 4-4.) If t zqxh z8 jqqrmg/m3/7af d(r*6he forward f/mf/g*qrqxda rzz8(jh 6 3m7 qorce on the more massive box is F, what is the tension in the connecting rope?

  Two boxes of masses m anv m3 /7di0eg. c6hlv pimw.oh2d 2m are connected by a rope. (See Fig. 4-4.) If the forward for.0 l.c2i6ghhovediwm v/ 3p7mce on 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 pulley4y+rx 0bswtw9 tjv6)* gyom l3 as shown in Fig. 4-5. Box I)4wt 3gr y +lo906wmbs*xvjyt of 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 3.0-kg bofctk 7ho;3 k)1ufeydtx pf (88x and a desk are 0.40 and 0.30, res8 cxo7f dyt;h)8tk3u( k1p fefpectively. What is the 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 on wood are 0.b lv0 el4hb75x50 and 0.40h5 b0lebxv 4l7,
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 comes e:3/lkqq e/um mlfebagdn*q2949+ trz;d n1z to a stop1ml*4 9gq:n3+ bf9a/l;edn q/zr tuz2qem ked 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 surfacughkt2 rfwa)7no6 sk* 4r x+y+e is pulled by a 5.0-N force. A 3.0-N friction force retards the motaf+)6wtsyu*kh o7x r+k2 4nrg ion. What is the acceleration of the object?

  A horizontal force of 5.0 N accu 05yse .kbss1elerates 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 gibf , ( z,hl7dmdv 8y/*fuvkxm-ven an initial speed of 10 m/s. It slides 50 m on the ice before it stops. What is th x(/7y8 fku*, mv-v,hmdfbldze coefficient of kinetic friction between the puck and the ice?

  During the investigation of a traffic 5,h.ul8 )6lfcq9gr me *bktlj9yiw -paccident, police find skid marks 90.0 m long. They h9rktbu -f)iy jl*e llqc w,8.m6g9p5determine the 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 surface betwafj/( aj/g.vdr8*bf* tov9 a heen the more massive box and the horizontal surface is smooth and the surface between the b f(.afbat h/8* jvv 9rg/*jdaooxes is rough. If the less massive box does not slide on the more massive box, what is the static friction force on the less massive box?

  Two boxes of masses m and 3m hr-jh,1vk+ rb are stacked. (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 brj+bh,h r1vk- ox, what is the coefficient of static friction between the boxes?

  An object is on a frictionlesscs +cdv2/f- ew inclined plane. The plane is inclined at an anglece s+w -cdvf2/ of $30^{\circ}$ with the horizontal. What is the object's acceleration?

  A 10-kg mass slides down a flat hill that makes an -cl9-g7ymx1le y+nxd3+ cz av 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 anpl((1 tzj1;rq uqp0 tnaln+r :gle 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 til* ; 1-z9rw fstzpi8duix0f-rn(ld ox6ted 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 rf-o2 bk )s+c/avom; 2udmf2iconstant velocity of / a2+ -voubfs2 rm 2o)di;fkcm6.0 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 massdb*,7hq6fnbfk*nzabtn4* 5 h m 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 slides downqroh2f)l*qde 49yw9(xngk;j 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 cable at4+ea8r mg jbl4tached to the+8bj4mgl rae 4 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)yehbu9i o j5/yz3aje* ed8me77 u 6xr rest on a rough inclined plane tilted at an angle of ee 6uadizyuj7 o/h7e5*x)3 rebm8y9 j $33.5^{\circ}$ 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 pm 9 c:bc(e4pnrn qkzu.17(kaned 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 p:c((r kpea.71 k4nn 9bucqzmcoefficient of static friction between the object and the plane?