Which of Newton's laws best explains why motpttkntyt:8n *v, m hq3 l8w)3iorists should buckle-up?

  When you sit on a chair, the resultant force on yo8;57y9 xephq mhksz7 fu is

  In the absence of an external qx4usn1po-,*f bq 1(fyhjma8 force, a moving object will

  When the rocket engines on the starship NO-PAIN-NO-GAIN are suddenly tulgi2a68s1axx rned off, while traveling in emp l6xa1ixas28 gty space, the starship will

  A rocket moves through empty space .i10aho u98e(8q fp hr f1jfepin a straight line with constant speed. It is far from the gravf p1pa(he1j8 q0h i.rufo 8fe9itational effect 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 movinquw2 fyt4h+2mfjy7 ;rp( n;mag bus, facing forward, and you suddenly fall forward. You can imply from this mp47h2yqwm;uaf ;+t yj(2 r nfthat the bus's

  You are standing in a moving bus, facing forward, and you suddenly fall wry)g i:e4g u9forward as the bus comes to an imyr4gw9 :guei) mediate stop. What force caused you to fall forward?

  A constant net force acts on an object. Describe the motion of the objecc*p*6x.q 6l9ovr kd gkt.

  The acceleration of an object is inversely proportionsj9 h*okt9h2 oq) q09xm cf.mnal to

  A net force F accelerates a mass m with an acceleration a. If the same n0bg r* aj8kl;cet force is applied to mass 2m, then the acceler ca*k;8grbl j0ation will be

  A net force F acts on a mass m and produces an acceleration a. Whaye/,vb f--qxnt acceleration results if a n eqx/,yn-v-fb et force 2F acts on mass 4m?

  If you blow up a balloon, and then release it, thet/ycn6jrum) u fju (srdd+() ,n0md4 j balloon will fly away. This is an illustratn )d jrr u6,+t)j(sfmjdd u/0ymuc (n4ion of

  Two cars collide head-on. At every motol3c2(fwp3n5y)j io ment during the collision, the magnitude of the force the first car ex2it3y 5pnj3loof) (wcerts on the second is exactly equal to the magnitude of the force the second car exerts on the first. This is an example of

  If you exert a force F on an onmwfy56 a 933 uftukn,bject, the force which the object exerts on you wilay,5n3u9m6u knt3wf fl

  Action-reaction forces03,frgkptdui xw5r7p fj:t;gc 4nk 5) u53hys

  Action-reaction forces apmu hu-;3 :pfyre

  A 20-ton truck collides with a 1500-lb car and causes a ln)6 l:fr(yi ynnvx)ch 65uo1xot of damage to the car. Since a lot of d1n (norfnlc6x hy)vx )u: iy56amage is done on the car

  An object of mass m sits on a rrs7ua -so1tvhrax w 8492oo k6) 9bkrflat table. The Earth pulls on this object with force mg, which we will call the action force.hw6roukots4o28b k-79 r)vs r 1x9aar What is the reaction force?

  A child's toy is suspended from the ceiling by means of pr+5bwps 22tyim5tg (a string. The Earth pulls downward on the toy with its weight forceg +p(py2i25mr bttsw5 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 qfmfho+-3/xrinstantaneous force. The ball hits the bat wim+ roq -f3hf/xth an instantaneous force, whose magnitude is

State Newton's three rzg 2;m/6aa msdl(le* laws.

  Mass and weight

  The acceleration due to gravity is q985fsw kin-alower on the Moon than on Earth. Which of the followingqn5aw9 sik8f- is 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 i ookp* , o8hh1org9 vlm.v+0qjs

  Who has a greater weight to mass ratio, a person weighing 400 N or a personrhy-lx,i1yv /t 7(z 9tdv4g oi weighing 600tth79 /4yig1vo dilzyx(r- ,v N?

  A stone is thrown straight up. At the top of its path,qjxa(8se x 4 xbs/kj-2 the net force acting on it kx2 j /8-bxejs4ax q(sis

  A 20-N weight and a 5.0-N weigh kz5bzii8qj 7 fs9 lhq,+i-:vjt are dropped simultaneously from the same height. Ignore air98v -b ,i+7ji kl:hq5sz zjfiq resistance. Compare their accelerations.

  A brick and a feather fall to the earth at their r 2s65jim)vg6s(ca do xespective terminal velocities. Which object experiences thcs6 o (s)img265dxvaje greater force of air friction?

  An object of mass m is hanfm*ufcb8n ft(o9a *(m ging by a string from the ceiling of an elevator. The elevator is moving up at(f9mmo bfa8(cfnt*u * constant speed. What is the tension in the string?

  An object of mass m i,vlbi8.imtgnk. 9 7 jys hanging by a string from the ceiling of an elevator. The elevator is moving upward, but slowing down. What is the tension in the,9 gjt.bmnviy 7kl.8i string?

  The force that keeps you from sli,x udn(y7 ra5 c0bpml)ding on an icy sidewalk is

  It's more difficult to start2flgp 8b0qg9f mhb y/) moving a heavy carton from rest than it is to keep pushing it with constant velocigy2p9l0/fhqbb g8 m f)ty, because

  A horizontal force accelerates a bop1tp6*yiq kn5qw,l8 (yj/ qkbx from rest across a horizontal 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 h y wpy q*/qipt8,j5q1(n6kk blappens to the box's acceleration?

  A packing crate slides do,0eavo fd xr)w8r(+oe8em u2opg(ih(wn an inclined ramp at constant velocity. Thus we can vr2 e)dg 8m+ e( uhw8poe0x(f,ooai (rdeduce that

  A block of mass M slides du 0y14 ;1eo/pnwx it(2;fn w3qx wlcypown a frictionless plane inclined at an angle q with the horizontal. The normal reaction force exer2n31wwiyctl ne0(y x o px4fp;;1qwu/ted by the plane on the block is

  A block of mass M slides down a frbz/dj)kk+ nxh zp.(y ix/qs:2ictionless plane inclined at an angle q with the horizontal. The normal reaction force exertzk:2yx) jdi.b/kz+n h/ qs(pxed by the plane on the block is directed

  A block of mass M slides down a fc(5lwq69 c4x s--fc 5lsnkbbx rictionless plane inclined at an angle q with the horizontal. The gravitational force icf5-4 scl5xxk w (9l6bqns-bcs directed

  Two toy cars (16 kg and 2.0 kg) are 8 pp4bpiz2bg (released simultaneously on an inclined plane that makes an angle of 30e with the horizontal. Make a statement which best describes their acceleratibp4 gpz(pib2 8on after being released.

  An object sits on a frictionless surface. A 16-N forcyc3hz r,g(- zk/ 6b 3lwfuqh)pe is applied to the object, anlcuhy3hgk/ rp )z,zwq 6-b(3f d it accelerates at $2.0 \; m/s^2$. What is the mass of the object?

  A sports car of mass 1000 u g(-cmftii0) bc.9 uxkg can accelerate from rest to 27 m/s in 7.0 s. What is thecf0mx ) uu.9ib-c (itg average forward force on the car?

  Starting from rest, a 4.0-kg body reaches a speed of 8.0 m/s i do(fj*qs 5puw +ymr2;g-igv4n 2.0 s. What is the net force acting on the g*jym5g iuo4q2 +pdw; frvs(- body?

  An antitank weapon fires a 3bs*:p.vu++n/v1koebwa j :cvm :8cuk yp6k5x.00-kg rocket which acquires a speed of 50.0 m/s aftera. /mb6 +vy5skxeu+v1kjukpcpn8 v*cw:ob :: traveling
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 fokeh0 *srk3kk s-;vrb2rce that you push a 10-kg mass from reste kv;sk-r0sk*2 rhb3k,

  What is the mass of a person who weighs 110 l n 28hohkl10sob?

  What is the mass of an xmpi/tp2a+ yar em+6:object that weighs 250 N on the surface of the Earth where the acceleration due to gm++tx /m6aia2e:ryp pravity is $9.80 \; m/s^2$?

  An object has a mass of 60 kg on the Earth. What is the mass of tmr r* q,8fii)rhe object on the surface of the Moon where the acceleration due to gravity isr qr)i,*8 ifmr only 1/6 of that on the Earth?

  Object A weighs 40 N on Earth, and object B weighs 40 N on tgbpadimep z /e./v-of6h44hwv-4r 6k he Moon. The Moon's gravity is onpo6 mi/ 44fehdrhb4v gp--e6vka. wz/e sixth of Earth's. Compare the masses of the objects.

  Sue and Sean are having a tug-of-war by pulling on opposite ends of a 5.p)zn -c z+dg fzq:h3/h0-kg rope. Sue zq zch+pdzg) h-n3:/fpulls 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 a level frictionless surface.d - b*qcw-9aqrs6i.ry 1cf3 vz A force F acts on the stack, and it acceleratacwcd 39bqrq1siz v-y *-fr 6.es 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 elev.l3u i1psardcuu* *;vator. What will the scale be reading when the elevator is accelerating dow;.riuplscv d u*a1*3unward at $4.00 \; m/s^2$?

  A person on a scale rides in an elevator.of(,i4nujv- (hve8f mkbpla-r; ;n*s If the mass of the person is 60.0 kg and the elevator accelerates downward with;-*vob j eh (ai p4u8,l(vfnf;rk-m sn 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 oy/r):i,ktv zj- k;k zef the person is 60.0 kg and the elevator accelerates upward with an accelerai,e krk-tv jz;y) zk/:tion of $4.90 \; m/s^2$, what is the reading on the scale?

  Two horizontal forces .8gsewhlsx1)tg /nbc0c .-ihact on a 5.0-kg mass. One force has a magnitude of 8.0 N and is directed due north. The second force towg) -8.hw /gs0 hcsb ite.xl1ncard 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 flatbed of a truck. Ivz q+wkb9s pi h-:(p0tt 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 wzs+9tkp0(h bp qiv:-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 (nm(vt 0 gw,fe29z,amgste o1place by m0,9f 2 e(mevgs1 tzgmo w,tn(aetal 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 cab?

  In the Atwood machine shownt5 a v9gu2ywe.sg,nl 8h*b-kr in Fig. 4-1, if M = 0.60 kg and m = 0.40 kg, what is t-b hey rt v9 ,a5s2.*nugkglw8he magnitude of the acceleration of the system? (Ignore friction and the mass of the pulley.)

  In the Atwood machine shown in Fig. 4-1, if M = tia3nec o+p*/0.60 kg and m = 0.40 kg, what is the tension in the +*3iepta cno/string? (Ignore friction and the mass of the pulley.)

  A student pulls a box of books on a smooth horizontal floor with a forceb muf /1,ri2ir of 100 N iimf1 /ir,b2run 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 -+r( mc;q mik +, i9a5wt mpcq9g(mwhhbooks on a smooth horizontal floor with a force of 100 N in a direction of iw + thqh5mc mg+ pm,q99;ci- wm(kra(37.0e 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 tb;ln b;9oly2tz2lp: 100 N is supported by two ropes as shown in Fig. 4-2. What are the tensions in ;l pl29btn :2lyo;zbtthe ropes?

  In Fig. 4-2, if the tensions in ie qqs9k,.0 jxthe ropes are 50 N, what is the mass of the traffic ljqqs90 kx.e i,ight?

  Two boxes of masses m and 2m are in contact with each other on a frictionles ,ov:dyh4sw5 is surface. (See Fig. 4-3.) What is the acceleration of the more mad yw, i:vs4o5hssive box?

  Two boxes of masses m and 2m are in contact with each other on a frictionls er0p()*hjou ess surface. (See Fig. 4-3.) Wha p0*urse)h(o jt is the net force on the more massive box?

  Two boxes of masses m+)tc kee3v*3 l fu9rit and 2m are connected by a rope. (See Fig. 4-4.) If the forward force ontit+3c93lere k uvf)* the more massive box is F, what is the tension in the connecting rope?

  Two boxes of masses m and 2m are connect 7 -s(i) wf-ta6lfxaqzed by a rope. (See Fig. 4-4.) If the forward force on the more massive box is F, what is the acceleration of the less maa6sqz 7x taiwl (f-)f-ssive box?

Two boxes are connected by a cord running over a pulley as shown in Fig. 4xz3p x1 ,ch0.. rhjbwg-5. Bor1h x.3 g.hxp zcbjw,0x I 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 9be2g 1qkc3vofrictions between a 3.0-kg box and a desk are 0.40 and 0.30cq2 ogb9v3e k1, respectively. What is the net force on the box when a 15 N horizontal force is applied to the box?

  The coefficients of static a f( agbh3-mn .a8e/bt+zq .yumnd kinetic frictions for plastic on wood are 0.50 and 0.gyb3- .tehab (+nm8f/zu.m a q40,
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 y+xob tts9/mp -8fx5h 4 xiyra;4.uz wslows and comes to a stop with p/xxht9zs5-4fr; +8ty a x uw4ibom.ya 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 by a 5.0-N for*;dieb-v q r4.xb/ sgdce. A 3.0-N friction force retards the motion. What is the acceleration of th qv.s*4d-bx /;geribde object?

  A horizontal force of 5.0 N acd+ve- k kg3- zcdg.*og7ggso2celerates 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 giqjtcawsp.- 98ven an initial speed of 10 m/s. It slides 50 m on the ice before t-ajp8s9c.wqit stops. What is the coefficient of kinetic friction between the puck and the ice?

  During the investigation of a traffic accident, police d6laac68aq0,hi7vsi6(oh si find skid marks 90.0 m long. They determine the so(d7hv 8isah 0ia6aqi,6 lc6coefficient 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 bet(s q foo:)c/miween 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, /:f)cqo mo(s iwhat is the static friction force on the less massive box?

  Two boxes of masses m and 3m are stacked.)r *hqbt-tyhvs sv/(, a-d/r c (See Fig. 4-6.) The surface between the more massive bb-*hrsc a)t/tvs,-dv qhr/(y ox 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 friction between the boxes?

  An object is on a frictionless inclined plane. The planz(k )pit dp3t8e is inclined at an angle of (p3t )zt8idkp$30^{\circ}$ with the horizontal. What is the object's acceleration?

  A 10-kg mass slides down a flat hill that makes an angle s40 yry(9p.raj2bwqk 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 w,+6lfvsb-nqrr : nzy0 ith 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 smoorcwjr- 2;.si*d.spn z th inclined 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 di22p8 ige prg7irectly down an inclined plane, at a constant velocity of 6.0 m/sr2 piieg 8g2p7.
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 a rout/0u9o6rxv k+ k khw4sgh $37^{\circ}$ inclined plane where the coefficient of kinetic friction is 0.20. What is the acceleration of the object?

  An object with a mass 70g2hc)f 5 gepi;gv;0 whi mizm slides 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 sur87hvby 7j; uy /dpgj:yface. The cable attached to the log makes an ajg :ph;yb/8vj7ydy u 7ngle 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 plane t,nh*5 *y cqoqxmz)4b2w tc f+rilted at an angle o* t4)q cwh,x +2zfronyc 5mb*qf $33.5^{\circ}$ 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 gradua0p5n yfw6+i.zu7zr5.p gpmkl lly increased until the object begins to slide. The angle at which this occurs is q. What i zfpz.5 mk w5.npylu70+gpr6 is the coefficient of static friction between the object and the plane?