Which of Newton's laws best explains why motorists shouldp**h:dgz:o siz9li 0 z buckle-up?

  When you sit on a chair, the resulta(,0exe*u pxl9dvos j,sz0) ctnt force on you is

  In the absence of an external force, a movi*ric7bszm(m -ng object will

  When the rocket engines on the tu vy6m/c,z2genrtlh,c/ z3. starship NO-PAIN-NO-GAIN are suddenly turned off, hc,tnegm ltc6z z 3,u.r2/ yv/while traveling in empty space, the starship will

  A rocket moves through empty space in a straight line with constant spee;k7s t o5qb 5mnss;8qwd. It is far from the gravitational effect of anqnst; s8 oms7qw;k55 by 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 buw2)eoj3szpt ph;8 tf6 d5c7jn s, facing forward, and you suddenly fall forward. You can imply from this thaec j5njt7ot;df) p p2zw86h 3st the bus's

  You are standing in a moving bus, facing forward,)/- 8b ae29ymur sxntv and you suddenly fall forward as the bus comes to an immedia umn-r 2ebxt yv)9sa/8te stop. What force caused you to fall forward?

  A constant net force acts on an object. Describqw4b xwq+81z se the motion of the object.

  The acceleration of an object is inversely proportigj0 v 6c0wym*eonal to

  A net force F accelerates a mass m od +v,i)r jde 1-mulo*with an acceleration a. If the same net force is applied to mass e*lr+ ,uom)ov1 d d-ij2m, then the acceleration will be

  A net force F acts on a mass m and produces an*9*er+ qe m5qwylf/eva cuxpn*c- y0 :e;poj - acceleration a. What acceleration results if a net *pvjpn e eem/-q;9 5yr e +**xcua:0qwyofc-lforce 2F acts on mass 4m?

  If you blow up a balloon, and then releaseh 9nffr:wdfwt8 l/ky;i0g q8- it, the balloon will fly away. This is an illuft 98r:/yf8ww0 ik- fl;n gdhqstration of

  Two cars collide head-on. At eve( dzd4gwgw0q4pq 4uk/ ry 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 exeq0(gqw4 wd/4 kud4g pzrts on the first. This is an example of

  If you exert a force F on an object, the force whichtfdv ;c-3xe3a4qr2eo5 cm1 ce-d;d f k the object exerts on you wi;3dkerd 2;5cocm-fdc ef t3va 4xq-1ell

  Action-reaction forces27oeu-l tfc r3

  Action-reaction forcesz-p. fio+h 1vg are

  A 20-ton truck collides with a 1500-lb car and causes a lot of damage to v 0,;unla, w;b6hlqx5cj 1z(m+dn lnrthe car. Si5l+0u,wm1ajnlxbcq rv; h;6 lnn dz(,nce a lot of damage is done on the car

  An object of mass m sits on a flat table. The Earth pulls on this object withvvr-i)m j4fp1 force mg, which we will call4r-v)1jvmi pf the action force. What is the reaction force?

  A child's toy is suspended from the ceiling by means of ep:i2j7vwv: ,6mjf cqa string. The Earth pulls downward on the toy with its weight force of 8.0 N. If this is the "action force," what is the "reaction force"?7jje:cv,v:pqi2 w fm6

  Your bat hits the bale(z zz uc 5)z t(hkt hy4 yfb90etz7h1+t7v9lkl pitched to you with a 1500-N instantaneous force. The ball hits the bat with an instant5 yvlkhetezt+ 0k7c)tht(7z uzfb1h z4(y9 z9aneous force, whose magnitude is

State Newton's three law)n-mon.fead 9 s.

  Mass and weight

  The acceleration due to gravity is lower on the Moon than on Egr ky8)jm dm,6arth. Which of the following is true about the mass and weight of an astronaut on the Moon's surfacemmd8j r6)k,gy, compared to Earth?

  An example of a force which acts at a 5f2tx75aw qd zlpxq1topb/,n *zhi 75distance is

  Who has a greater weight to mass ratio, a person weighing 400 N o9g5m: dk;wl3zhvh: u j3;r py:0y rtbur a person weighingdrpkv;0ghu::w93z3r;5 j t uylhm:b y 600 N?

  A stone is thrown straight up. At the top of its path, the net force acqux,p9 b: ,vaf8yp . q5spy+wfting on ivfp:s9x 5 y,u+8q.w,bayqfp pt is

  A 20-N weight and a 5.0-N weight are dropped simultaneously from +vw (hw1ifxo my8q72cq *xx5kthe same height. Ignore air resistance. Compare their accelef(+w*hxyw 5c2qkmi 8vo7x1qxrations.

  A brick and a feather fall to the ear55e1xjjap oyzq-xw( j +)o cj1ci /le1th at their respective terminal velocities. Wa- o1ycj1jix)+ej1 /cx55plz qjweo( hich object experiences the greater force of air friction?

  An object of mass m is hanging by a string from the ceiling of aq0 piynhg::-v sen5c 7 p* mf.i+jb*nkn elevator. The elevator is moving up0.+ pe5gk hs: c- i yj7i*qnpvbfm:n*n at constant speed. What is the tension in the string?

  An object of mass m is hanging by a string from theyl:tnvcr2 yj:xx o(rw-84/f zk ;f-qe ceiling of an elevator. The elevator is m yv8rxw2z / ff nokcrlj4e:t:x-(-q y;oving upward, but slowing down. What is the tension in the string?

  The force that keeps you from sliding on an icy sidewalk is fhnh* f:x7s 8,klhp8s

  It's more difficult t, eydb )yrbd7+o start moving a heavy carton from rest than it is to keep pushing it with constant velocity, becauseyyrb +7 e)db,d

  A horizontal force accelerates a box from revwrlxcqog cpelf ;5y7 ,h r2:4z4+ nv9st across a horizontal surface (friction is present) at v9r+g cwh,:ln2oe l7fyq5x 4zp 4vrc; 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 veloci()n0fk7xvyxwh9 bw ,g ty. Thus we can de)b,h k7gf 0wy(9xxnwvduce that

  A block of mass M slides down a frictionless plane inclinlz v.p(3)rbbh-c ktf3ed at an angle q with the horizontal. The normal reaction forc)pbtl3vc3rh (.-z bfk e exerted by the plane on the block is

  A block of mass M slides do p3,t w)ucdfl-wn a frictionless plane inclined at an angle q with the horizontal. The normal reaction force e -wfd3c), uptlxerted by the plane on the block is directed

  A block of mass M slides down a frictiodbm9 uv-cddfgbl9 mqfq,lf c ;9*x: -)nless plane inclined at an angle q with the horizontal. The gravitational dqcd9 q9; -mc xdl)u *b,fm fg-9vb:flforce is directed

  Two toy cars (16 kg and 2.0 kg) are released simultaneously on an aqh:+i/ + evxyinclined plane that makes an angle of 30e with the horizontal. Make a statement which best describes their acceleration aft:a+xe/ih+v qy er being released.

  An object sits on a frictionless surb,j . r0y gf;8k.vukpaface. A 16-N force is applied to the object, and it accelerug.krv ap0k;y .jf8 ,bates at $2.0 \; m/s^2$. What is the mass of the object?

  A sports car of mass 1000 kg can accelerate from rest kbw*+a8 c qlso q;,n*ito 27 m/s in 7.0 s. What is th+8owianq qb;* ks*cl,e average forward force on the car?

  Starting from rest, a 4.0-kg body reaches a speed of 8.0 m/s inkj(cerxo:iji.2a)b + 2.0 s. What is the net force acting on the boi+).a oj 2krbjxci:(e dy?

  An antitank weapon fires a 3.00-kg rocket which acquires a speed of 506ibt.kp4l9y.es/ivjhy4 nz(o26h n p .0 m/s after traztl y b ppo94(kiv.nnh2h./ 4yej6i6sveling
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 fro+d5j1y.xyg (5ktev hcm recx+jeg h1vtd.k 5yy(5st,

  What is the mass of a person wh;d av/ru7gb5+ si-qvie2fqo, * g1vrqo weighs 110 lb?

  What is the mass of an object that weif;3pflv0 gbwu6f zv;5 (quzyrl 0rz -5ghs 250 N on the surface of the Earth where the acceleration dy;uulvzrvzz5 6; pr l5qb0(f0 gfw 3-fue to gravity is $9.80 \; m/s^2$?

  An object has a mass of 60 kg on the Earth. Whats8g q*jrx)c;q.u7dcr is the mass of the object on the surface of the Moon where the acceleration due qc8u* rx;gdj)qrs 7.c 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 )gsdoi bn)w8x:.goh6 the Moon. The Moon's g)oxg):swi68.ob gdh nravity is one sixth of Earth's. Compare the masses of the objects.

  Sue and Sean are having a tug-of-war 1 d*a;bv:.xvuphxy)*bobw+f by pulling on opposite ends of a 5.0-kg rope. Su v d;+1v:boh* yx.fa)*xpbw bue pulls with 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 on+6se)te3eof 8y;uy- jjtk pw 6siwu,, a level frictionless surface. A force F acts on the stack, and it acceleratty-w;tje8 6 eep3fu )i+w yo,s6ks,ujes 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 an elevatrg14 y rxznygm57j) 9uor. What will the scale be reading when the elevator is acceleratigxzy jg 4rn9)17u5ym rng downward at $4.00 \; m/s^2$?

  A person on a scale ridesl8g0aml( q v6osd, ,9n govsm/ in an elevator. If the mass of the person is 60.0 kg and the elevator accelerates downward with an acceleratg/ovsmgs,q 96 ,va(nld o08 mlion of $4.90 \; m/s^2$, what is the reading on the scale?

  A person on a scale rides in an e : si5x4;h+xm.o nrjw be1f1kplevator. If the mass of the person is 60.0 kg and the elevator accelerates up1+x nbs1 4fpx:je 5 ikrhmo.;wward 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 *5p3c/f rmr9mt rsj:khzs07k has a magnitude of 8.0 N and is directed due north. The second force toward the easz / f3pms90*5sr7m hrk kc:jrtt has a magnitude of 6.0 N. What is the acceleration of the mass?

  An object of mass 6000 kg rests on tnu6*;ucnd 8d k y*lu.lhe 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 travel* dy ;8udl*lk6uu.n cning 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 flatbed of a truck. It is held in.3q26 zwgm ul*hoi ,tp 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 time if the load is not to slide forward into the cut2lop*ghq.i3 6 mw,zab?

  In the Atwood machine shown in Fig.evt-y0--b 8 ,z7tqsetrcm 4sw 4-1, if M = 0.60 kg and m = 0.40 kg, what is the magnitude of the acceleration of the system? (Ignorwtev-et7zscm,4b8rt s0- -yqe friction and the mass of the pulley.)

  In the Atwood machine shown in Fig. 4-1, if M = 0.s;-p kvt b3bd.60 kg and m = 0.40 kg, what is thb;p k-sb.dtv3e tension in the string? (Ignore friction and the mass of the pulley.)

  A student pulls a box of books on a smooth horizontal f q7 fdgd g+3;ngmi,ftp- l1rw6loor with a force of 100 N in a dir1w -n,fptfd r m7 dg3+ql6i;ggection 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 force of 10 m)-d;y3vg ;vj*uw7 jvv0z 5s gmzsi9s0 N in a direction of 37.0e above the horizontal. If the mass ov;s*g myisvw5m ;zv3-gjzd09 )7 ujsvf 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 ( l;ndysb5 9qcfroxgpm. ;)n. two ropes as shown in Fig. 4-2. What are the ;b;rs(5x ) pn 9fomgdq. .nlcytensions in the ropes?

  In Fig. 4-2, if the tensions in6naqf1s.q,auh 4j w0z the ropes are 50 N, what is the mass of the traffia.q0ahwf64 s,1nzjqu c light?

  Two boxes of masses m and 2m are in contact wihg e3)(zzs6l:n wbx)ga bih)6 ku0c /bth each other on a frictionless surface. (See Fig. 4-3.) u3z:)azgbx6)e0n /h 6gbb (w)s lhkic What is the acceleration of the more massive box?

  Two boxes of masses m and 2m are x 0 8lw/ii1ivikwyf5c8ei 5w*in contact with each other on a frictionless surface. (See Fig. 4-3.) What is theefi0iv/l kiy8 15i w85wwx ci* net force on the more massive box?

  Two boxes of masses m and 2m are connected by a rope. (See Fig 6nj: 1ozqz87v7nbm;m ; zai-u:px frg. 4-4.) If the forward force on the more massive box is F,j; :mqr:upz bof az87-6;x7niz1 nvgm what is the tension in the connecting rope?

  Two boxes of masses m and rw6e4baiai7 g5.t 1yo 2m are connected by a rope. (See Fig. 4-4.) If the forai ebg.to7wr 46y ia15ward force 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 pulley as shown in Figcp .8z30ex rym. 4-5. Box I of may03 pmc8xzr.e ss
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 box and a desk mx 97e*gpo*dfare 0.40 and 0.30, respectively. What is the net force on the box when a 15 N horizox9d7f **pgoemntal force is applied to the box?

  The coefficients of static and )ttfm2msy 01skinetic frictions for plastic on wood are 0.50 and 0 m1m2s0t)tysf.40,
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 zg/2j.f- 7 ox fr5evwblevel surface in the +x direction. It slows and comes to a stop with a constanf2rojbe/v-fwx5z. g7 t 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 by a 5.0-N force. A 0fa8g l (cmv 6d/zq-xx3.0-N friction force rexq/ -g(x6 cf8 lmz0vdatards the motion. What is the acceleration of the object?

  A horizontal force of 5.0 N accelerates a 4.0-kg mass, from 5i94a6y 1hg::p+n+pj g kks +yvq emxnrest, 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 initpa 3zj9px -h2szq6:luial speed of 10 m/s. It slides 50 m on the ice before it stops. Wha 92jz xhppqz-:3al6sut is the coefficient of kinetic friction between the puck and the ice?

  During the investigation of a traffic a)g+9gdl t9 c fqo:cb9eccident, police find skid marks 90.0 m long. They determine the coefficient of fricq9l t9db) ccg+o9fge:tion 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 n;mb6ds39k 5vii q fqf(b01rbs1oap 1between the more invbr;1 1baf (m6sof 9q05 i1qkbs p3dmassive 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 friction force on the less massive box?

  Two boxes of masses m and 3m yu n0vww kcmcky 7t6sl7g iyca)4*889 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 box, what is the coefficient of static frictiock c4 i6ny8yv*st0g)yw7c7lu a8 w9mkn between the boxes?

  An object is on a frictionless inclined planevndxo5rph 7+r,riq 70. The plane is inclined at an anglr+ro,0xiqn ph5v7 rd7e of $30^{\circ}$ with the horizontal. What is the object's acceleration?

  A 10-kg mass slides down a flat hill that makes an angleg +1bsmq 1o 9qfhib3*t 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 angle j0md.f nc(psv9u) sa ;5sjyc/.mh .dmof $37^{\circ}$ 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 planez:ebgll o my :589ga* jwlw(a6 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 constant 4cuaj1rp5f a 5velocity of5p u af45rcj1a 6.0 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 mass m slides down4qr;vw rj yf10 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 down a rou0tzn6: efo 2v(y.pduwn er )0tgh $37^{\circ}$ 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 surfaceoj 0 +dxtl4vm za;0h4v. The cable attached t4 xvloj4 dht+z0m;0avo the 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 ro () elphc5l27ex3dwdk p/dfu: ugh inclined plane tilted at an angle 7)u5heped2:x /( wfc l3pldd kof $33.5^{\circ}$ 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 graduallola d(7it,mo h adc+0(y increased until the oboh( o7,a0lddma( +ic tject begins to slide. The angle at which this occurs is q. What is the coefficient of static friction between the object and the plane?