Which of Newton's la5esj3to 71zmj5j qivo 6*v /ekws best explains why motorists should buckle-up?

  When you sit on a ch vi zc c8fv;4fu7kw/,; su,sbnair, the resultant force on you is

  In the absence of an external force, a moving object wiehcc ;qpu+ ,y,ll

  When the rocket engines on the starshi b;pps6/ bh k3lu 4zwd,(zt,gcp NO-PAIN-NO-GAIN are suddenly turned off, while traveling in empty space, the 6p ,bpzkc;h3ugb(l4/,w tzsdstarship will

  A rocket moves through empty space in a straight line with consi jqq;-yh-w7i tant speed. It is far from they-hqjq i ;-i7w gravitational 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 movins)fed-h6 6an gg bus, facing forward, and you suddenly fall forward. Y- a)d 6shgefn6ou can imply from this that the bus's

  You are standing in a movinj9e-gx nf mp 0b/i52hlhr /o4ob8idr)g bus, facing forward, and you suddenly fall forward as the bus comes to an immediate stop. What force caused you to fall for pl0gfox98do)ie-4mj //nhbbr ih2r 5ward?

  A constant net force acts on an object. Desc cmme4 +.csd(uribe the motion of the object.

  The acceleration of an object is inversely propon 2v*cf(2.; kqpbqbfl1k8njirtional to

  A net force F accelerates a mass m with an acceleration a. If the same nef.ld elj2v nso u ro3o3l8l28;t force is applied to mass 2m, then the accel jv8;fruodl. so3l38el2l2oneration will be

  A net force F acts on a mass m and produces an acceleration a. What acceleratiorsow ,9f*y pm*n s*wpyrf m*o 9,results if a net force 2F acts on mass 4m?

  If you blow up a balloon, and then release it, the balloon will fly away. wzyyz4-9ba n(fn: ;qf,qtr5 e This is an illustr wq4fq 5na;yztyze:- f 9(bn,ration of

  Two cars collide head-on. At every moment during u0rk5ie v g lm7hsej6b,. 7le+9rsi0s the collision, the magnitude of the force the first car exerts on the second is exactly equal to the magnitude of the force the second7.l m us9lvies+0g erk065b,rie7sjh car exerts on the first. This is an example of

  If you exert a force F on an obv.p ;lpgt)u(bpu. n/ yject, the force which the object exerts on you wil;uuty/ l ) pvg..pp(nbl

  Action-reaction forces+ a2 m .8:ibgarlpywr)+ bis1f

  Action-reaction forces arelsteg5 ddmb5 o ll/ic:m06)6 z

  A 20-ton truck collides with a 1500-lb ca8ne pk:s 7fmi8)cb.5x s6b)ef zqmbp.r and causes a lot of damage to the car. Since a lot of:sqbp8 bi m 6 )p5.cmx.ez bek)ffs87n damage is done on the car

  An object of mass m sits on a flat table. The m1y)th1 ) aj2ezmbc,vEarth pulls on this object with force t1mv ))e zcmyb1a,jh2 mg, which we will call the action force. What is the reaction force?

  A child's toy is suspended from the ceiling by means ofacidk9y, wl; mud*5v0z*h8 w+oool*k a string. The Earth pulls downward on the toy with its weight force of 8.0 N. Ifl9l*zkhicy *o wa+;,dkuo vm0 d5 8o*w this is the "action force," what is the "reaction force"?

  Your bat hits the ball pitched to you with a 1500-N instantaneous for c1 rvc0).mjo 2852zlxfsbjrc3m omd6 ce. The ball hits the bat with an instantaneous force, whose mc8 ol c1c0mbsm2j 6 x3rd5f2m).zrvjoagnitude is

State Newton's three y*rzi4ms4i y zo3 1e5luv(;r5-wfdkilaws.

  Mass and weight

  The acceleration due to gravity is lower on the Moon cpq9r:evb3 ,a*b bg(cthan on Earth. Which of the follvpbccb*e(g39 :qa ,r bowing is true about the mass and weight of an astronaut on the Moon's surface, compared to Earth?

  An example of a force which aw3j/8j m idr(ycts at a distance is

  Who has a greater weight to mass hixzfa q)u f83c xu(+7ratio, a person weighing 400 N or a person weighifz hxqxf(3i)uca u+78 ng 600 N?

  A stone is thrown straight up. At the top of its path, the net force acting on 6l7 st7opa2so/o lwco5 y7f2jocjy/ 7o7 52loats2o7s l6wpfit is

  A 20-N weight and a 2jr. gbb* .,jnm,oj w p:pr5a/2atoia5.0-N weight are dropped simultaneously from the same height. Ignore air resistance. Com5oar j:, jn.r.b2t gmai w2p/apj,b*opare their accelerations.

  A brick and a feather fall to the earth at their respectcib,6tj1 raiw:q- l-+v gx78nx an/tnive terminal velocities. Which object experiences thn-l1gtcj8t, :x- 6aq + nwibiarxn/7ve greater force of air friction?

  An object of mass m is hanging by a string from the ceiling of an elevator. q;e-(qr dngk2wc;6 aj ,xsf u1The elevator is moving up at constant speed. What is the tension in the str26g -rwe n;q;(sj,q1 uk fcdxaing?

  An object of mass m is hanging bdre3c*d2(pvr: wx.;yc gq (ptab/n+ yy a string from the ceiling of an elevator. The elevator is moving upwadrr( *tpbge:; 2x pyc+3d/w cn.y avq(rd, but slowing down. What is the tension in the string?

  The force that keeps you from sliding on an icy sidewalk 74yen zjpdsw(z9 9/mh 9qe q9eis

  It's more difficult to start moving a heavy carton from rest than it d)gz m ds 6(re*zfhd(9is to keep pushing it with constantzdg9( rh fzm6d*e()s d velocity, because

  A horizontal force accelerates a box :m2 o:uvomuk2,t+lmj lyz2q ) from rest across a horizontal surface (friction is present) at a constant rate. The experiment is repeated, and all conditions+lvt umjyzo:q ol)m2, k:um2 2 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 velocity. Thus we cbcrp-cwg8a65: ;6bmwnso u,e an deduce tharc8o,;bnbpgmc5:6wu 6 s-wae t

  A block of mass M slides down a frictionless plane inclined at /9h3b(fe h uz) avd7msbv(z bj tn3s:5an angle q with the horizontal. The normal reaction foj :sb53uh v bsd7n)emf3b(vza(h 9t/z rce exerted by the plane on the block is

  A block of mass M slides down a frictionless plane inclined at an angle q .l*0ywxj jn-e with the hole wjjx0n-. y*rizontal. The normal reaction force exerted by the plane on the block is directed

  A block of mass M slides down a frictionless plane inclined at an angle28khz,em xf4/r c wx1qn1wp t4 q with the x/4 e1fmxw1c8r hwpzk,nqt 24horizontal. The gravitational force is directed

  Two toy cars (16 kg and 2zd0v ,-og xg:f2pmwzg os(a-4.0 kg) are released simultaneously on an inclined plane that makes an angle of 30e with the horizontal. Make a statement which best describes their acceleration after being rele mf sp4 :wxdogz(v -0go2,-agzased.

  An object sits on a frictionless surface. A 16-N force is applied to the obb8 3ys5 zm.v*n9zsrdb tk0scj;p(;z mject,rckm.szb zp syz;v0 5mj8( n*bs3td9; and it accelerates 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 2oosgsn5yad7cu53 f 1pe02qi 3 7 m/s in 7.0 s. What is the average forward force on the 3coig17ao ssq055 y ue npf2d3car?

  Starting from rest, a 4.0-kg body reaches a specasqxd9ojn10.0su3 led of 8.0 m/s in 2.0 s. What is the net force actino0qs0d 91u xl3acjns .g on the body?

  An antitank weapon fires a 3.00- ohon /:8sba1skg rocket which acquires a speed of 50.0 m/s after travelin n1a:8soohs/bg
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 1er7oq2yg j2(bpu 7s 2w0-kg mass from rest,2j 2rqsbw g(u y27oep7

  What is the mass of a person who weighszewe (403 x .nopn+/vxoimpc9a,f2qt 110 lb?

  What is the mass of an object that weiq 3ry ;olda:oyk2i7 yw-9ruf5ghs 250 N on the surface of the Earth where the acceleration due to gravityyw5u9yo2yrorld i :3; 7af-kq is $9.80 \; m/s^2$?

  An object has a mass of 60 kyx8r;tg jz8 :)tik*jjg on the Earth. What is the mass of the object on the surface of the Moon where the acceleration due to gravit j )yx*8;k8gzt: rijtjy is only 1/6 of that on the Earth?

  Object A weighs 40 N on Earth, and object B weighs 40 N oklyd(j62-u i(o1mff on the Moon. The Moon's gravity is one sixth of Earth'sklo jd2 fy 6i(fuo1m-(. Compare the masses of the objects.

  Sue and Sean are having a tug-of-war by pulling on opposite ends of a 5.0-kg r8hx tw9kmbh ):ope. Sue pulls8h)9kx :wmbth 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. A fovy9gq+2ivm85 vu 8yoorce F acts on the stack, and it acceleratesvoyqi9o v82 +8u vm5yg 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 stand0 a e:um6o7iqfs on a scale in an elevator. What will the scale be reading when the elevator is accelerating downward m7:06 ioueqaf at $4.00 \; m/s^2$?

  A person on a scale rides in an elevator. If the mass of the person is 60.0 l-0klrcat-h( ht t(zqr y534tkg and the elevator accelez4kctat -t0-r5y h(ll( h qrt3rates downward with an acceleration of $4.90 \; m/s^2$, what is the reading on the scale?

  A person on a scale rintm7v +4e1x2ewa lczv 6kve1/des in an elevator. If the mass of the person is 60.0 kg and the elevator accelera4 vln/6e vwx ek 1a2ev7zc1t+mtes 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 ar xdq:fu21sy9z q 4-zforce has a magnitude of 8.0 N and is directed due north. The s d9rq2-z :14ufqxazsyecond 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-5v kdej6 67ge1pvkyz 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 travel6 v ge-17py5vze dk6kjing 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 e(-owqzf1t3u rests on the flatbed of a truck. It is held in place by metal brackets that can exert a maximum horizezq- 1wfu (o3tontal 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 in Fig. 4-1, if M = 0.60 kg and bt0 :yrcc)f+jm.t g6ym = 0.40 kg, what is the magnitude of the acceleration of the system? (Ignor: c)ttryc.fyjg +6m0be friction and the mass of the pulley.)

  In the Atwood machine shown in Fig. 4-1, if M = 0.6xf69lfd - 2e6i)p plrk0 kg and m = 0.40 kg, what is the tension in the string? (Ignore friction andf -2x9k 6)ipel6rlfpd the mass of the pulley.)

  A student pulls a box of books on a smooth horizon 4brsl 47r.stftal floor with a force of 100 N in a direst4.rsb4 fl7r ction 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 hn6sr2dlw, h7xpru5 0ij8q(jbooks on a smooth horizontal floor with a force of 100 N in a direction of 37.0e above the horizoqj, h52pli6u jr0rs7h(wxn8dntal. 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-g c2hmf irk3d zm,n*0a9swx0 own in Fig. 4-2. What are the tension9xhg*wkd0zif ms 0,rcm3 n-2as in the ropes?

  In Fig. 4-2, if the tensions in the ropeseda6ir :5 r.7y/ kd w,c0ziwqk are 50 N, what is the mass of the traffic l:krw.ki qdcy6ai d0w7 /er5z,ight?

  Two boxes of masses m and 2m are in contact with each other on a frictionlessc +h/ c;)gi+bq i(gsj9o 8vgkj surface. (Seig8 b)ci;j +sqj(9 kvc ho+g/ge Fig. 4-3.) What is the acceleration of the more massive box?

  Two boxes of masses m v*yh46 :crvsp ch0 a)nll,r2eand 2m are in contact with each other on a frictionless surface. (See Fig. :cvv*0cpa rhy,26lhl4s)enr 4-3.) What is the net force on the more massive box?

  Two boxes of masses m and 2m are connected by a rope. (See Fig. 4-4.) e g85wnzr )/jw ity5y- If the forward force on the more massive box is F, what is the tension in the connecting ro8)j/ ny- 5yzrg5 etwwipe?

  Two boxes of masses ndotsj,5 j)-l 3uh4gb m and 2m are connected by a rope. (See Fig. 4-4.) If the forward force on th3ljt)-d,5ohs bj4u ng e more massive box is F, what is the acceleration of the less massive box?

Two boxes are connected by a cord running overow,)mp7hh;)tf ) cjkzl6e p)v a pulley as shown in Fig. 4-5. Bomlot6)zwjk7 )vhh p c ,e)p)f;x 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 frictiosiwe1*c :mg*q ns between a 3.0-kg box and a desk are 0.40 and 0.30, respectively. What is the n*e*cmi1ws g:qet force on the box when a 15 N horizontal force is applied to the box?

  The coefficients of static and kinetic fric3jlx9c.zal;6g ,o*t7i rdks ltions for plastic on wood are 0.50 and jol*z6gis,.t x 9alc l7kdr; 30.40,
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 level surface in the +x direction. It slfh0l ufc/t 6i4qrk .(gows and comes to a stop witcl4ti(.6 k/ff h0qrug h 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 by a 5.0-N forb7o) rll m9+,i c4cc2ciiu5vece. A 3.0-N friction force retards the motion. What is the acceleration of loricc 7vu9 5c2cbim)i el4 +,the object?

  A horizontal force of 5.0 N accelerates a 4.0-kg mass, from rest, at a rate of fa;37t y30z;t k rimvmdfyf /sm7n+t+$0.50 \; m/s^2$ in the positive direction. What friction force acts on the mass?

  During a hockey game, a puck is given an initial speeu,qzap 6w(clg+ s+m-0v l: rzvd of 10 m/s. It slides 50 m on the ice before it stops. What is the coefficient of kinetic friction between the puck c(6vw+q+vg ,a:spzzllm r0- u and the ice?

  During the investigation of a traffic accident, police find skid marks 90. w/ahj3 jdt5hb+,2cavf te7k -*g(wv j0 m long. They deter fckj25jt+w3h baevt 7ad g (-j*hvw,/mine 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. (Se)q - w46xz 3cpby-lhxye 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 sy bl xzh4)3y pqw6x-c-tatic friction force on the less massive box?

  Two boxes of masses m and 3m( 3oyfd7daw t-w+q0 au 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 boy adof-+ 3d0ww(ua7tqx, what is the coefficient of static friction between the boxes?

  An object is on a frictionless inclined plane. u2m0eili5lz zgz0 zaq 3r7+j0The plane is inclined at an angleu i25qimg0jrl0zl3 azzz0e7 + of $30^{\circ}$ with the horizontal. What is the object's acceleration?

  A 10-kg mass slides down a flat hill that makes an angle of g(eoimblm d1kk/n6wd ie1n 204r/fs* $10^{\circ}$ with the horizontal. If friction is negligible, what is the resultant force on the sled?

  A mass is placed on a smooth incljo06gf)cs )eq ined 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 inc )- -ptsoya4zflined 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 directly down an inclined plane, at a constantx0n1s nw uz*(t velocity of 6.0 m* xw0st(nnzu1 /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 lfr8r(lkbx 5) 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 down a ztwe6g(zls 93g/qj4wa y2ye- 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. Tvyvv oys/al bx.6kfv4 .3h8j;he cable attached to the log makes an angle s v3f.46;jkbo.xhlv a yv/8vy 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 releashsd5lt* v-1h jed from rest on a rough inclined plane tilted at an angle *sth dlj-h5v1of $33.5^{\circ}$ 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 o e wlj41a)c8y7d n6ymln an inclined 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 cce4j 17yd)mawlyl8 n6 oefficient of static friction between the object and the plane?