Which of Newton's la,-4yv m4o4r nxs k :+d7qocgjzws best explains why motorists should buckle-up?

  When you sit on a chair, the resultan wi4*dj4va g(jt force on you is

  In the absence of an external force, a7zquo1 q n:3agwf20py moving object will

  When the rocket engines on the starship NO-Pzhslsu t4n;f1 i52j0vh9x4 jjAIN-NO-GAIN are suddenly turned off, while traveling in empty space, the st5jjln041 jvufxs sz; h24h ti9arship will

  A rocket moves through empty space in a straight line with constant sszyynk 46zr x z.+cz:(peed. It is far from the gravitational effect of any star or planet. Under these conditions, x yz6rsyc.zzn(zk4+ : the force that must be applied to the rocket in order to sustain its motion is

  You are standing in a moving bus, facing forward,x;rgp05v3wh0zd0w5 dvy 6wie and you suddenly fall forward. You canwp x0v yd;rvdw6e 0hwzi0g535 imply from this that the bus's

  You are standing in a moving bus,-6z;l f0t6r;dhmz rg; xlya:/lzzt 1r facing forward, and you suddenly fall forward as the bus comes to an imm zallgd z6z-rym r;/r:0hlx;f;t1z6t ediate stop. What force caused you to fall forward?

  A constant net force acts on an object. Describdveg f wmfke )d9h/06-:z+ lyie the motion of the object.

  The acceleration of an object is inversely 0 6na hhk8s yt(:gm0bxproportional to

  A net force F accelerates a mass m with an acceleration a. If the same 0d5q9qbu0 blhba:md 8net force is abdl8 m b05:q bdu90qahpplied to mass 2m, then the acceleration will be

  A net force F acts on a mass m and produces an acceleration a. What acceleratiog(2g e1fmzy yr qei890n results if a net force 2F acts on mas2fy1 8iq gzgy09emre( s 4m?

  If you blow up a balloon, and then release 6* m,b u)lbfw 2gb)nfrit, the balloon will fly away. This is an illustration o2 br, mb)*g )ffnub6wlf

  Two cars collide head-on. At every moment during the collision, tv vb4a ks/8x0p m1hw:dhe magnitude of the force the first car exerts on the second is exactly equalwpm4xb:8 dv0a /sh1 kv 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 object, the force which the objecy 82ts.(00weo evlpxwq, j3vut exerts on you wites jewq 0, 0wou.y v(lp328vxll

  Action-reaction forces8lmmm4 - qwe1b

  Action-reaction forces are(qytuu0k k3g6

  A 20-ton truck collides w5*hvdcyv,z tlpf(gio:ph8u (o.b: z69e)npm ith a 1500-lb car and causes a lot of damage to the car. Since:mc69g *bd z( lhv)vf8ue(opnpi 5y h p.zt:,o a lot of damage is done on the car

  An object of mass m sizoqdv5p,h -ix0o.1mkts on a flat table. The Earth pulls on this object with force mg, which we will call the action force. What is theo 1,05 -qozmp.kxdvh i reaction force?

  A child's toy is suspended from the ceiling by means of a string. The Ebp/wm5m ao6ocy7 . q8,7gssbe arth pulls downward on the toy witmp5s.,y/6co8b sq 7g7b oeamwh its weight force 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 instantaneous force. The bake;b ovr8;2m fll hits the bat with an instantaneok;;f2b r8oevmus force, whose magnitude is

State Newton's three a:7k -elqf+s. v-fa xhlaws.

  Mass and weight

  The acceleration due to gravity is lower on the Moont:u )o8h9dxicoz g) ,;hjne 1q than on Earth. Which of the following is 8huj1h9q ,x cogiod)e nzt:);true about the mass and weight of an astronaut on the Moon's surface, compared to Earth?

  An example of a forcsjqr-e.wud/+v6g:f ye which acts at a distance is

  Who has a greater weightkmwz ld uz r7f*b3,0r *y 4y2dazj-0vv to mass ratio, a person weighing 400 N or a person weighinkz4 z2,uj b07l dvyrraf-zvy 03d*wm*g 600 N?

  A stone is thrown straight up. At the top of its path, the net force nb(hz7y x ch59acting on it isc 75 nhx9zybh(

  A 20-N weight and a 5. gb zn6vn36; pk3yzfc*0-N weight are dropped simultaneously from the same height. Ignore a3fc y;*z6 z6vgkn 3npbir resistance. Compare their accelerations.

  A brick and a feather fall to;krr da4odx tns9x7/iagi/k5u27 +x r the earth at their respective terminal velocities. t /+ 9k xsd dru kx4xo;r2r/7iag75nia Which object experiences the greater force of air friction?

  An object of mass m is hanging by a string from the ceilig,ezg+ 6x9y ) /wujadwng of an elevator. The elevator is moving up at consteu) z+9j6g w,dx /gawyant speed. What is the tension in the string?

  An object of mass m is hangol:1( juy o96:gxyjm (l6 lymling by a string from the ceiling of an elevator. The elevator is moving u9oj:ug6l lx:lyy1 6 m(mo(jyl pward, but slowing down. What is the tension in the string?

  The force that keeps you from slidinu ,x2e6 o;3udz)u )ls a :zs0jeuebak9g on an icy sidewalk is

  It's more difficult to start moving a heavy carton from rest than it is gpow fbd/l /(8to keep pushing it with/(f l8go wp/bd constant velocity, because

  A horizontal force accelerat2c nl. 0vsx3ehh qapwhv/39 4ies a box 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 happens to the box's acceh 3e/c wn.309vh2xpi 4q lhsavleration?

  A packing crate slides down+, h smqlm)yxig:o7e. an inclined ramp at constant velocity. Thus we can deduce ti gl)emomx,:sy7q. h+ hat

  A block of mass M slides down a fricpo(h2716qljn9kfca n 4k 1 y+u;chnattionless plane inclined at an angle q with the horizontal. T n7k l oah9 y6cjk2(+qn14cpnth;a1fuhe normal reaction force exerted by the plane on the block is

  A block of mass M slides down a frictionless plane inc )f1zipzmd(o4 lined at an angle q with the horizontal. The normal reaction force exerted by the plane on the block im( z)1dzfp4 ois directed

  A block of mass M slides down a frictionless plane inclined at an angle q wi6rde5:ph6 d 1:xeiggtth thdhix615pr:g gdte: e 6e horizontal. The gravitational force is directed

  Two toy cars (16 kg and 2.0 kg) are rel22 iysvw-c 9a3h ov2xaeased simultaneously on an inclined plane that makes an angle of 30e with the horizontal. Make a statement which best describesh3c-ys2xovw 2 2avia9 their acceleration after being released.

  An object sits on a frictionless surface. A 16-N force is applied to5j1 .0:w g bgqvocnvs8o2n,a n the object, and it acceleratesc :oj .2wgav8sonq10g,5nnbv at $2.0 \; m/s^2$. What is the mass of the object?

  A sports car of mass 1000 kg can acce ww lv93 -:0e2atflcmqjkmv5/lerate from rest to 27 m/s in 7.0 s. What is t30e mt -25:wcf v/9qlawlmj vkhe average forward force on the car?

  Starting from rest, a 4.0-kg body reaches a speed of 8 *56rdc+wrnn p,5sjzcl4n( wy.0 m/s in 2.0 s. What is t,w(r+np w*z d5sc y6n4nr5jclhe net force acting on the body?

  An antitank weapon f swg6 k::b,ijlires a 3.00-kg rocket which acquires a speed of 50.0 m/s afterwj: b,6lkg :si 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 witxrupbc,dwo. m 1 (/rv vpjm;4*h the same force that you push a 10-kg mass from rest,o, 1p(bcrv*wj4u v dm;.m rp/x

  What is the mass of a person who weighs 11 -2+fdxzyfw 6y0 lb?

  What is the mass of an object that weighs 250 N on g gd pxll(.e25jnbp*o: 2opx v)n ,x*hthe surface of the Earth where the acceleration nn x)v od:(pbx*l oh5.*2e,2pjlpg gx due to gravity is $9.80 \; m/s^2$?

  An object has a mass of 60 kg on the Earth. What is the mass of the oe3oh hh8-rwwv +r8h xe9wsi 1-bject on the surface of the Moon where the acceleration due to gravity is only 1/6 of that on the Earth?erre1x hsv-3- o88hww9hw+hi

  Object A weighs 40 N on Earth, and object B weighs 40 N on the Moonz v4kvyun4+1w;d5k cv. The Moon's gravity is one 1w;kd y4 vcn+kz5 u4vvsixth 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 c4qw p/:c tzfh*jof1-hx*nl:+zytt 45.0-kg rope. Sue pulls with a 15-N force. What is Sean's force if the rope accelerates towa j + q/:hpfchwc-1o4*4xlzn*: ttzftyrd Sue at $2.0 \; m/s^2$?

  A stack of books rests on a level frictionless surface. A force F acts on the cg 0zsrk6m(mn6*c( 2a/ytc k bstack, and ((sncy6abmk0 rtm6kc c g/ z*2it accelerates 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 stur23 2es2agfg ands on a scale in an elevator. What will the scale be r22 areu2g3fsgeading when the elevator is accelerating downward at $4.00 \; m/s^2$?

  A person on a scale rides in an eec1*n )skrxl 9f5m9 zblevator. If the mass of the person is 60.0 kg and the elevator accelerates downward with an acce1 5n9ec*kzmsbf)9xl r leration 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 o/n:/*x* p e3fmfrernvf the person is 60.0 kg and the elevator accelerates upward with an accelerx e3* r:/ efv/pfnn*mration 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 m0hrhi cq9 zxq-09) zg0gk hp2cagnitude of 8.0 N and is directed due north. The second force toward the east has a magnitude of 6.0 N. What is the acceleration of the ma2c9ghzq0i 9qgkx)zch 0 h r0p-ss?

  An object of mass 6000 kg rests on the flatbed of a truck. It is held y8n2k*kk6b6hj9khi* g0m,(x icgj pd 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 m ,phkdi6h*c8m0kjjn9 * gbi(6g2 k yxkinimum stopping distance if the load is not to slide forward into the cab?

  An object of mass 6000 kg remta3q1ufev22rt(3 0duwm te +sts on the flatbed of a truck. It is held in place by metal brackets that can exert (u0requvt3 3mt2m1+e dtw2afa 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 s 7o(c 6rhvyv(ghown in Fig. 4-1, if M = 0.60 kg and m = 0.40 kg, what is the magnitude of the acceleration of the system? (Ignr( hv( 67gvcoyore friction and the mass of the pulley.)

  In the Atwood machine s0n3.ju 6b2 +) auly1xmoovn qmhown in Fig. 4-1, if M = 0.60 kg and m = 0.40 kg, what is the tension in the string? (Ignore friction and the masqaj. 620 +youx omn3)b1luvn ms of the pulley.)

  A student pulls a box of books on a smooth horizontal floor with a forcee +vs zh7; fec-wraeg +*t;h-p of 100 N in a +h+wect;hz7 va-sp*r-eg ef;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 s4x s*,uykl1hamooth horizontal 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 isyxu kl4a1h ,s* the normal force on the box?

  A traffic light of weight 100 N is supported by two ropes as shown in F 8g ,i9hosjm0lcof1z 2ig. 4-2. What are the j lmohz 89ofc0 1g,si2tensions in the ropes?

  In Fig. 4-2, if the tensions in t ../nbra 4 3vm:xtjy /tk8jgmqhe ropes are 50 N, what is the mass of the traffic lig y:vqb3/.k4m.x ng aj 8rjm/ttht?

  Two boxes of masses m and 2m are in contact wit xofs7qe);f sh7e/oypw15iu il)o,e * h each other on a frictionless surface. (See Fig. 4-3.) What is the acceleration of the more massive box h w7 * )5eei1fpfxs)yoo;ueosq7, li/?

  Two boxes of masses m and 2m are in contact with each other on a frictionlcq. potsy:5t,uin8 t7 ess surface. (See Fig. 4-3.) What is the net force on the more massive box?o,c7tq i pt8s :.ntuy5

  Two boxes of masses m and 2m are connected by a rope. (See Fig. 4hn7-iku8x z3 v8xf 5zy-4.) If the forward force on the more massive box z58zhxn8yu xf-vi k37is 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.) If the8 coy)c;ob yx/ forward force on the more massive box is F, wh cx y8yo/;b)ocat is the acceleration of the less massive box?

Two boxes are connected by a cord runnintf9ym2 ywg8/fg over a pulley as shown in Fig. 4-5. Box I otgf2/9ywf 8 ymf 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 frictions9b m;2tpx4y8rm hlejb-+ + dkd 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 horizon+-rhe4b 9kxl 8d jmdm;typ2+btal force is applied to the box?

  The coefficients of stau 3wgxw*q9,k b9zlo:atic and kinetic frictions for plastic on wood are 0.50 and 0.o*w3zglxka9uwq ,9 b: 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 dirbnr4(3 qfahw wo,d0,l oyh(ok q1r77iection. It slows and comes to a stop with a constant ach1rb 73dofr(oq4ay w7 k,ni o0w,hl(qceleration 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)p st; raflx1m a3si8* force. A 3.0-N friction force retards the motion. What is the acceleration o)l arf3 t*; 8pismsx1af the object?

  A horizontal force of 5.0 N acceler):lw(4x y ydqrates 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 puc :-day 4 fo4a6zmsocg6g i6-msth(s *lk is given an initial speed of 10 m/s. It slides 50 m on the ice before it stops. What is the coefficio als4tasg6f ch6mg4-d -*m (s: yi6zoent of kinetic friction between the puck and the ice?

  During the investigation of a traffic accident, police fi jc/*f /3/fptyld q:kend skid marks 90.0 m long. They determine the coefficdlpfjqft*c/k e/ :3y /ient 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-) e3v(ui ujbx*/a( qx d3(h hs7ohib(n6.) 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 isnsbi (qbv(xj/(h3 )(*x7ehdauo3h ui the static friction force on the less massive box?

  Two boxes of masses m and 3m are stacked. (See Fig. 4-6.) eg6so,fzm).m i8dw tg7z4in5db+wr0The 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 0) ni wms+ zd4m7ib6 58gzt ,erog.fdwfriction between the boxes?

  An object is on a frictionless inclined plane. The mmng7bg j; wk.v h: p-hmvi(0m**ua(uplane is inclined at an angle of m :gh*v.mhvik(a7mug0 (jnm-uw*; pb$30^{\circ}$ with the horizontal. What is the object's acceleration?

  A 10-kg mass slides down a flat hill that gvd.xwm3g93c makes 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 smooth inclined plane with aoyh :7jqt6v:f n 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 tilted at an ahviaxc0h.8q5h .)p5j b:in/wq qo ste04gn4 ingle 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 velocitxw8gj 5y,khl3 y c,ef5y of ,f,e8jc3wh5 kg5yxyl6.0 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 down :woc)o2 vyv p6zy*nw: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 * e oprdr6nbb+5xhr8 u:*hwo-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 surface. The cable attay*n yeldnpqn,3n5j - +wuu(2b chednp luny 3j (b5,-+wqnune2y*d 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 rough inclined plane tigo2pyh-p( o m7oi9 z(alted at an anglep7yz- m9oa(h2(pio go of $33.5^{\circ}$ 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 odr gc*j 0*w:t3 hk6pez wyx5chlg* (8mn an inclined plane. The angle of incline is gradually increased until the object begins to slide. The angle at which this occu zg**tylp (d3r5wc 0xj hh we6c*:m8kgrs is q. What is the coefficient of static friction between the object and the plane?