Which of Newton's laws best expf d(*uq0xtvt8 lains why motorists should buckle-up?

  When you sit on a chair, the resultant force on you is0hc3 u45ty( f mt2reip

  In the absence of anf )i((e91*nml uyvm ak external force, a moving object will

  When the rocket enginq0ih3 tv: r,jnes on the starship NO-PAIN-NO-GAIN are suddenly turned off, while traveling in evi3,q: nj hr0tmpty space, the starship will

  A rocket moves through empty space i4o 6u6, a,5 r6crp1zqta mersun a straight line with constant speed. It is far from the gravitatr,4eaompc6qr 6urt au ,1 z6s5ional 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 moving bus, a g bdg0guck23 ex jt/4q7cb56facing forward, and you suddenly fall forward. You can imply from this that the xg debt473a/kcgu0 cjb5g26q bus's

  You are standing in a moving bus, facing forward, and yrq(b3g rwg;:6lq 6ll gou suddenly fall forward as the bus comes :qg;36qgg (lrrwll b6to an immediate stop. What force caused you to fall forward?

  A constant net force acts on an object. Describe the motion of thz( bu2 sky+x03d:2ua exqcxi3 e object.

  The acceleration of an object is inversely proportional td5ex5j6ga.hv qp4l)njr :h sf.oy 2k9o

  A net force F acceleratg;llufcl zmq9dm +f+l t8 3x37es a mass m with an acceleration a. If the same net force i3lfl8m m3 lf+ d7qxgzct;l9+u s applied to mass 2m, then the acceleration will be

  A net force F acts ozb5 1wdpd: 1je:b s,thn a mass m and produces an acceleration a. What acceleratiop1 z:j5 :t1d,s hwedbbn results if a net force 2F acts on mass 4m?

  If you blow up a balloon, and then reb+lpoze-;py5 n 7 j7 awm,uqj9lease it, the balloon will fly away. This is an illustration aql jp7 mu+jy-7p;oebzw9n ,5of

  Two cars collide head-on. At every mome.uh fu8j0w1n)nyw1 dent 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 on ufe0jw)ywh 81.n1d un the first. This is an example of

  If you exert a force F on an object, the force whf8hp,9fmx2h5 * be-m d5tw/rf-cb djnich the object exerts on you wilphcw -fn bfe8,m2/* d 5mrjb9t5- fdhxl

  Action-reaction forceszcz;9ki p 4ee(

  Action-reaction forcesnd;e 9- tm)8g+gvxp .agp-n wv are

  A 20-ton truck collides with a 1500-lb car and causes a lot of damage to x.brsed t4m2hz4 74sithe car.44s hr ezti4mds2.b x7 Since a lot of damage is done on the car

  An object of mass m sits on a flat table. The Earth pulls on this objecrpd0 ;y6v(bgonm r5y2 t with force mg, which we will call the ayrg bn(20mvyo5 6d;prction force. What is the reaction force?

  A child's toy is suspended from the ceiling by means )1gun4bsi4v(7 h vdv6x-1 xx;gh xgycof a string. The Earth pulls downward on the toy with its weight force of 8.0 N. If this ixi41 c- 6v7v;hhv xs g)xdub14gx(yngs the "action force," what is the "reaction force"?

  Your bat hits the ball pitched to you with a 1500-N instantaneous force.+4 oeis3hanmz1l c xmuq;+1m/ The ball hits the bat with ax1 lm; 3+c omh /a41sz+quinemn instantaneous force, whose magnitude is

State Newton's three la.w) xu3b. ,l wgt :jlfio/dyr*ws.

  Mass and weight

  The acceleration due to gravity is lower on the Mkoe4gj* 84eio wtjr 1bcm 8p97oon than on Earth. Which of the following is true about the mass and weight of an astronaut on the Moon's surface, compa m 9jiwbje1r 8c*peoko784t4 gred to Earth?

  An example of a force which acts at a disflxxe (k-y4e5yzu0y9tance is

  Who has a greater weight to mass ratio, a person weigh cgr1 o1qrehhzvph 72t6k6p00fx t*.s ing 400 N or a person weighingroh7gh fqth1 c p.kr 2v*6sepzx1t600 600 N?

  A stone is thrown straight up. At the top of its path, the netq7+jgma i wu4- force acting on it w4mju aigq-7+is

  A 20-N weight and a 5.0-N weight are dropped simultaneously from the same heigm g+ekg.cl +d,:ewwxff1 /ah, ht. Ignore air resistac/ . ex df,+he:1klw wm+gfa,gnce. Compare their accelerations.

  A brick and a feather fap 3o,acvykscy/ /8lv,n z3x-bll to the earth at their respective terminal velocities. Which object experiences the greater force of ai3oy3bc/-pa8yl/cv,v n , zksx r friction?

  An object of mass m is hanging by a string from the ceiliulxz7yo 7m .i/rzhqf 6web8+6w3v nx:rl e;i: ng of an elevator. The elevewhioez m8+rxq7z; 6:ury:w6v ixblf . 3nl /7ator is moving up at constant speed. What is the tension in the string?

  An object of mass m is hanging by a string from the ceilm v3z0 j4l*qxjing of an elevator. The elevator is moving upward, but slowing down. What is the tension in the str43lv0 zjmxqj* ing?

  The force that keeps you frblwi-5kip +; oom sliding on an icy sidewalk is

  It's more difficult to start mowk0hw15c y.om o/.fvor xp+ .gving a heavy carton from rest than it is to keep o/xm w+vo0 k1wfg.5.co rhp y.pushing it with constant velocity, because

  A horizontal force accelerates a box from rest acr88d7 bqzid/oyqq+e s -oss 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 yo eq -bqsq7+/dz 88didoubled. What happens to the box's acceleration?

  A packing crate slides down an inclined ramp at const o.: ulk0yep)jdl;i0y ant velocity. Thus we can deduce ou:.lplydk ;i)ej0 y 0that

  A block of mass M slides down a frictionless pa eiyb 5f(c6 -w.q*uhblane inclined at an angle q with the horizontal. The normal wea5y(h-if *b.uc6qb reaction force exerted by the plane on the block is

  A block of mass M slides down a frictionless plane inclineri6 p7tm;av tu/2jl6rstial c,. z/(bd at an angle q with the horizontal. The normal reaction force exerted by the plane on the bl/2 urttbr6,pal7 (.tmz/ i6a;jiscv lock is directed

  A block of mass M slides down a frictionless pb arp+ +a)yfhvop)8/hlane inclined at an angle q with the horizonta+ fvyh+hbpoara) /)8pl. The gravitational force is directed

  Two toy cars (16 kg and 2.0 kg) are released simutmr7/l9set gh,+/ r)p9 oazpx23h up wltaneously on an inclined plane that makes an angle of 30e with the horizontal. Make a statement which best dlrp37 hmew/z+p t9o/,s)x 9hta2pur gescribes their acceleration after being released.

  An object sits on a frictimb1omq,17h/tk b(g4qh k 7xoionless surface. A 16-N force is applied to the object, and it accelerates at 1ixb mq m7bhkog (o471kqht,/$2.0 \; m/s^2$. What is the mass of the object?

  A sports car of mass 1000 kg ,lglm 7sq*,wu rx30iacan accelerate from rest to 27 m/s in 7.0 s. What is the average gm3 7wui0xql*r a,,slforward force on the car?

  Starting from rest, a 4.0-kg body reaches a speed of 8.0 m/s i r /k)* 1v-t7dge)3k y3 wqt4mrqpr6la5nkdzfn 2.0 s. What is dkazl34qw fr)tq71)mperkt nv5rk/- 3g* 6dythe net force acting on the body?

  An antitank weapon fires a 3.00-kg rocket whim*em3j ts3 apgu8 1i,ikjuy/+ch acquires a speed of 50.0 m/s afteue, m/y13 mgp*3ji8 sja+iutkr 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 wnh*m;,.)xp l nxoi duokayq. av6r/)3ith the same force that you push a 10-kg mass from rest,u)o m, k/lxovda y.36;.prn) qi*n axh

  What is the mass of a person who wg( 1hzx72c /rktfn)63yvj lh zeighs 110 lb?

  What is the mass of an object that weighs 250 N on the surface of the Eaj: o(8:h krdmjrth where the acceleration due to gravity is jm :jr:o(dk8h $9.80 \; m/s^2$?

  An object has a mass of 60 kg on the Earth. What grn 8n ,7pu kw5l8nb4cis the mass of the object on the surface of the Mo4npl krw ng75bn8,8 cuon 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 weighwgqfh(o*8vk tge- z70s 40 N on the Moon. The Moon's gravity is one sixth of Earth's. Compzt( -7 fkg80*wqh evogare the masses of the objects.

  Sue and Sean are having a tug-of-war by pulling on opposite ends of a 5.0-k5xbs9y ,j:xyi 1 ahdcp4kf,hc ;u3(2ao ng/owg rope. Sue pulls with a 15-N force. What is Sean's forc 95/ca4od(x,gxi;wof,1b nh2kyh cj sy:upa3 e if the rope accelerates toward Sue at $2.0 \; m/s^2$?

  A stack of books rests on a level frictionless surface uwovi(v ;6) cl+axpm0. A force F acts on the stack, and it accele(mvxop 0+)w6luvc; iarates 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 elevator. What will tey8c ,ij: zqte4,h(v,xphy6 vhe scale be reading when the elevator is accelzi vxec(ty,6,hehy:j8v4,q p erating downward at $4.00 \; m/s^2$?

  A person on a scale rides in an elevator. If tit.8 mh,bg6pihe mass of the person is 60.0 kg and the elevator accelerates downwar6 i8.itb m,pghd 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.(e nz n/6l;;mwcfs6j 9*lnqvq0 kg and the elevator accelerates ;vcz6 m6s ;f(enlnj n/wqq9l*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 has a magnitude of5rooo95 c ps 4ubkw08g 8.0 N and o po0gukswb5 5cr4 8o9is 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 rests on the flatbed of a truck. It is held i6wib :- 2mvw bnx5;eiwk4: eyan place by metal brackets tb:;b:kyn4 i5emi w v2-ae6wxwhat 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 cab?

  An object of mass 6000 kg rests on the flatbj lxad41fht ack/9hn4h:n t0b, 1e btcgr/ /,aed of a truck. It is held in place by metal brb : ch/ka91/htb,r0nlax 41aj enctd,t fg/h4ackets 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 shown +p )lgj4 sdgvj.v ,mywqg*c 74in Fig. 4-1, if M = 0.60 kg and m = 0.40 kg, what is the magnitude of the acceleration of t,.cjg)g4gy4v7+vjq*pwd l s m he system? (Ignore friction and the mass of the pulley.)

  In the Atwood machine shown in Fig. 4-1, :ttrd 7 4cxivq/q 7q8dif M = 0.60 kg and m = 0.40 kg, what is the tension in the string? (Ignore fri7ct7d x4t i:/rdq q8vqction and the mass of the pulley.)

  A student pulls a box of books on a smooth horizoze8z l)3:hl2sf lle,sntal floor with a force of 100 N in a direszh3: l,e8 l)fzesll2ction 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 boxtcuz)o8 abu) : of books on a smooth horizontal floor with a force of 100 N in a direction of 37.0e above tau)o8zu : tc)bhe 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 a2fk.g pt-x2zz s shown in Fig. 4-2. t -2zpzgfk.2x What are the tensions in the ropes?

  In Fig. 4-2, if the tensions in the r ks1zxschk lhf:.g(8dl) j8f.opes are 50 N, what is the mass of the traffic ligh:88x(s )jdl.f l1fzchksg . kht?

  Two boxes of masses m and 2m arm:g,u nd1xiy2 ha.sdn:jq(7 ye in contact with each other on a frictionless surface. (See Fig. dgsy( .:m1, nhjq a y7x:duni24-3.) What is the acceleration of the more massive box?

  Two boxes of masses ucm1b,+g( s1dqb p.:(cem brl m and 2m are in contact with each other on a frictionless surface. (See Fig. 4-3.) What is the net fdmc1u r :qbbc(l .1spm(+bg,eorce on the more massive box?

  Two boxes of masses m and 2m are conne r2klt(d(fxqwrj6 r14 cted by a rope. (See Fig. 4-4.) If the forward force on the more massive bowrrqf2 (k 14 j(l6xtrdx is F, what is the tension in the connecting rope?

  Two boxes of masses m and 2m are connected by a rope. (See Fig. 4-4. r6mxl*fe cbgr v0k.32,qewu2) If the forward force on the more massive box is F,r*geu vk.cr0 b,l6qex m2f2w 3 what is the acceleration of the less massive box?

Two boxes are connected by a cord running over a pul irqc ;vha+5:aley as shown in Fig. 4-5. Box I o;vq iraha c+5:f 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 stuhqrtx5p2q 4- atic and kinetic frictions between a 3.0-kg box and a desk are 0.40 and 0.30, respectively. What is the net force on the box when a 15 N horizontal force i5 4phqx-tr u2qs applied to the box?

  The coefficients of static and kinetic frictions for plastic on:6hs- rgajwa 0sge )w0 wood are 0.50 and 0.4w60j-a e 0ga)swg:shr0,
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 q/:b ba2 ighm+level surface in the +x direction. It slows and comes to a stop with a constant aca mbbq/:+ hig2celeration 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.e*qv-yao -to) A 3.0-N friction force retards the motion. What is the acceleration of )*aqy-v t ooe-the object?

  A horizontal force of 5.0 N accelerateba/fl 04t. omxs 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 give0hqex ppsx ;*8we4i d0n an initial speed of 10 m/s. It slides 50 m on the ice before it stops. What is the coefficient of kinetic friwhie;x0d8 xq0p pe *s4ction between the puck and the ice?

  During the investigation of av jce3o23 kc7k traffic accident, police find skid marks 90.0 m long. They deterje7c2kvk o3 3cmine 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.;z -zk2eu2hen) The surface between the more massive box and the horizontal surface is smooth and the surface between the boxes is rough. kz n ;h-22zeeuIf 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 are stacked. (See Fig. 4-6.) The s8 js6mug*lg3)m 5 d4wqbjla)wurface between the more massive box and the horizontal surface is smooth and the surface between the bom8blgg 5d6a l*sj4u)jqwm3)w xes 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 plane is inbvd-yn1b s4 o(clined at an angleyvsn ob(1 4-db of $30^{\circ}$ with the horizontal. What is the object's acceleration?

  A 10-kg mass slides down a flat hill that makqyx k8:a2 2gsp-3.q(rfrgwq y 2oep*bes 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 smnks.y1cz( ul5wa*.6zf9le q+t e v7oiooth inclined plane 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 inclined plane tilz+coxc9sn6v) ted 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,nktzr0b-d7 +n+dcjnoli; py t-8 2ez* at a constant velocity of 6.0;zy dt+n-ni7dn o-2 jz*ctkebp80+l r 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 dow-me8 +dogx/ m47cqud7j: j/ zlxagu.on 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 slg f. dd+h+q p,2sau+qdst2+o hides 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 5e+ fvpy- bf4flyut6 zpvm;)6.00 N along a rough surface. The cable attached mtfpf yy6uf;vb 4 +e-z .vl6p)to 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 qcl4 t 5t1-(ph0svutn rough inclined plane tilted at an angle u( cn 5q-tv0ht1lsp t4of $33.5^{\circ}$ 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 )ye j67m2r oul;xphq0 angle of incline is gradually increased until the object begins to slide. The amleou0;6 p2q 7r)yjxhngle at which this occurs is q. What is the coefficient of static friction between the object and the plane?