Which of Newton's laws best explains why:bjw ),vh n.,dgkwpa( motorists should buckle-up?

  When you sit on a chair, the resultag.v t6 3jddaw+nt force on you is

  In the absence of an external force, a czoa te. +: x6d3+11l svdsodpmoving object will

  When the rocket engines on the starship NO-PA,/frv,(jjo pa IN-NO-GAIN are suddenly turned off, while traveling i(ja/v j f,,porn empty space, the starship will

  A rocket moves through empty space in a straight line with constant spk ip31s*lk cu9eed. It is fa3ks1lpc u* 9ikr from the 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 moving bus, f /aao tywulk9pp xn9 n):62wx,wyb6f8acing forward, and you suddenly fall forward. You can imply from b6)un96k8 ywaf x/ o ,ln9xppww: yta2this that the bus's

  You are standing in a moving bus, facing forward, and yhr25p s6-eeo acw u pg/nz62e)ou suddenly fall forward as t rwzup n5c/6)hg 2e-eosep2a 6he bus comes to an immediate stop. What force caused you to fall forward?

  A constant net force acts on an /-e-l kcpmaglb0m5 i r2*m *azobject. Describe the motion of the object.

  The acceleration of an object is inversely proportiona 8h)bi2olv/uwo+ 5*g,8cs;wqi uvd hll to

  A net force F accelerates a mass m with an acce,js78 mqjtp(hwr kr 1pvo7ojxdf ../7leration a. If the same net force is applied to mass 2m, then the accelerati1jk 7. q wo7.f jj(vhs7xmpd/ptor8r,on will be

  A net force F acts on a mass m andj5j9v x 8fgjy/fot7- x produces an acceleration a. What acceleration results if j89yjfj7 g ox/ -5xftva net force 2F acts on mass 4m?

  If you blow up a balloon, and then release it, the ballo r07y zcs w:cipt+(-5ilec,cwon will fly away. This is ac7ty(cs:5zicer- ,+l pwci 0w n illustration of

  Two cars collide head-on. At every moment during thlf8hfn 2y,t6 j)(eai ae collision, the magnitude of the anjf8)tf(i, l 6e2yhaforce the first car exerts 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 object, the force which the object 5l/gplh z5v b0exerts on you wilbll p 5h0/5zgvl

  Action-reaction forch3pgus8mqf;), 2 alej es

  Action-reaction forces )u j2revni6: :)r zal 9;erkefare

  A 20-ton truck collides with a 1500-lb car and causes a lfdqt/ zeizu10dzm8b03 p 8w-aot of damage to the car. Since a lot of damage is done - e 0f3 d1mza08pb tizwu8/zdqon the car

  An object of mass m sits on a flat table. The Eait1 *jkcn+)x irth pulls on this object with force mg, which we will call the action force. What is the reactioncxij+tk* n i)1 force?

  A child's toy is suspended from the ceiling by means of a stript shkm p2n m+g5i9a+*ng. 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 forh km5ntis2 g9ap*++pmce"?

  Your bat hits the ball pitched to jlb)e8fn qef(g 98us5c81xjs you with a 1500-N instantaneous force. The ball hits the bat with an instantaneouefes8 gu8x(n1 f 9cb85)lsjqjs force, whose magnitude is

State Newton's three lawr cf53 cxw p3*yw1 cs7gn1i6hjs.

  Mass and weight

  The acceleration due to gravivkhvy7 vigo1 nx b eich37;7.;ty is lower on the Moon than on Earth. Which of the following is true abo;hkv;nvcih71.7 3g b7v oiyx eut the mass and weight of an astronaut on the Moon's surface, compared to Earth?

  An example of a force which acts at a distan h3b0igr 1 -vkc/fzcw/ce is

  Who has a greater weight to mass ratio, a person weighing 400 N ordj; t r 5th8y,yx31jfe a person weighing 6 j38x ;eytyr1htf dj,500 N?

  A stone is thrown straight up. At the top of its path, the net force actrwfe90vmj59rf .vkdx 884jb oing on ix8fjr5vo . k4jdfe98 m0rv wb9t is

  A 20-N weight and a 5.0-N weight are dropped simultaneou8vb 4 puo; , 59k qnvv3ldr2;il7yjlwosly from the same height. n4 wq3odlil k5ypv,v7uv;rjob8; l29Ignore air resistance. Compare their accelerations.

  A brick and a feather fall to the earth atz6mjuf k+ qj8p6uxp( * their respective terminal velocities. Which object experiences the greater force of air p*6u6qzum+8pk x (f jjfriction?

  An object of mass m is hanging by a string from the ceiling of an elevator. Thhqsz6) h; mpthoe13jk,s)b 3m e elevator is moving up at constant hm 6h s)opem3;,)hjts1qk zb3speed. What is the tension in the string?

  An object of mass m is hanging by a string froggi( ppv3k3v2,kuw+uv, 3cqe m the ceiling of an elevator. The elevato+gik,,2 ve3uvwpc gq3v3u (pk r is moving upward, but slowing down. What is the tension in the string?

  The force that keeps you from sliding on an icy sidewau9ml(00+-yi kn zsdlilk is

  It's more difficult to start moving a heavy crchtei5 pur,t5:fy1 )arton from rest than it is to keep pushing r )t5rhftcip5, 1u:eyit with constant velocity, because

  A horizontal force accelerates a box from rest across a hz /bo44j4hlphorizontal surface (friction is present) at a constant rate. T z 44jo4phblh/he 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 dowm9c lahgti6)yg 1/r0t n an inclined ramp at constant velocity. Thus we can deac)rgy hig m/06 19tltduce that

  A block of mass M slides down a ay;rt3rwz 6r,l)ehnl n9.0 n wfrictionless plane inclined at an angle q with the horizontal. The normal reaz l3nah9e 0;6w,rntl r ).nywrction force exerted by the plane on the block is

  A block of mass M slides down a frictionless plane inclinr8,ah6rovz uu6thg: 9ed at an angle q with the horizontal. The normal reaction force exerted by the plane on the bloh9gru6o 6h8t aruz:,v ck is directed

  A block of mass M slides do cyq o6mw3o/p5wn a frictionless plane inclined at an angle q with the horiw5p o3qoc/m6 yzontal. The gravitational force is directed

  Two toy cars (16 kg and 2.0 kg) are released simultaneously on an inclined pl/g9osgs:up g5 c+:qra s- 4uysane that makes an angle of 30e with the horizontal. Make a statement which best describes tc4us-+:s 5 ogspsuqg9/a :r ygheir acceleration after being released.

  An object sits on a frictionless surface c3.;dcfh:dky . A 16-N force is applied to the object3y d. dfc;h:kc, 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 27 m/s in 7.rkl2tb 8g)w.4wpcn 2:n kv hp10 s. What pct4nr g2:2w hl.n)bw vk8k 1pis the average forward force on the car?

  Starting from rest, a 4.0-kg body/chm xw t:1jkd*3ji vt eh*e+; reaches a speed of 8.0 m/s in 2.0 s. What is the net j*mi + 3e kw tdjv;/1*ehct:xhforce acting on the body?

  An antitank weapon fires a 3.00-kg rocket which acquires a spepch9) 3dqdu 5wed of 50.0 m/s after trud5 w)39phcd qaveling
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 se k6 34lolvr)dame force that you push a 10-kg mass from resdkv6)el43r lot,

  What is the mass of a person who wjp x.pwr t(qe1e5cj,sc .bs49eighs 110 lb?

  What is the mass of an object that weighs 250 N on the surface of the Ear(4rs+3jfgqee,hmtpo r 6aj 6 6th where the acceleration due to gravity r+4r(3h6 ojm j,et6p a6fqgesis $9.80 \; m/s^2$?

  An object has a mass of 60 kg to4ev4p)u q/ewr vj.6on the Earth. What is the mass of the object on the surface of the Moon where the acceleration due to gravity is only 14p/6 ej.evovw)tuqr4/6 of that on the Earth?

  Object A weighs 40 N on sjgd32/ z n+qlEarth, and object B weighs 40 N on the Moon. The Moon's gravity is one sixthz sdq+j/2 3gln of Earth's. Compare the masses of the objects.

  Sue and Sean are having a tug-of- (o)6vbm7 y+ ej tex6), ,pzf1cntksmkm2dx9 nwar by pulling on opposite ends of a 5.0-kg rope. Sue pulls with a 15-N force. What is bx)7ev2t(mj9 ,pzk6cn +x, kymto1m)d6 en fs 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 force l)iim pl 2aer(dhg-bf 813ks ()sds5t F acts on the stack, and it accelerates at b23ds)ak8(lt5h1l s)riispem gdf -( $3.0 \; m/s^2$. 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 elevato.as7t4f:ay6 j q(aziur. What will the scale be readin4qauy7asaf6z t:ji (.g when the elevator is accelerating downward at $4.00 \; m/s^2$?

  A person on a scale rides in an elevator. If z56fb(x/qmx /g3flisncdwk.5 2 k.e wthe mass of the person is 60.0 kg and the elevator accelerates downward with a5w/ 2e5/.x3q nw gxcfb (kilmfz.6s dkn 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 60.0 kg c aohwpr(ak(fy j54 8. i0+nqwand the elevator k p.( war8+h(cjn0i a4f5oqw yaccelerates 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 tooj)n81la3fz6-y ;f zb dyr/force has a magnitude of 8.0 N and is directed due north. The secon)yr 8of b 3nz ydz1foa/lj;t-6d 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 tpzp,brxt.+oze 3wr p(u )l90xruck. It is held in place by metal brackets that can exert a maximum horizontal force of 9000 N. W+x9o3z .(p,zpprbxluw e )rt0hen 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 thzh9o5xk hu 5hf yc0:3ce 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 traveling 15 m/s, what is the minimum stopping time if the load is not to slidh5c0 hzckyf9 h5x3 u:oe forward into the cab?

  In the Atwood machine shown in Fig. 4-1, if M = 0.60 kg and m = 0.40 kg, what c/+,oi/d-fp 1vjjfyg1y +sx r is the magnitude of the acceleration of the system? (Ignore friction and the mass of the /,v11px-fr+yf ijdyc/ sj+gopulley.)

  In the Atwood machine shown in Fig. 4-1, if M = 0.60 kg and m = si0fl0w1kwvgs 0gv,3 0.40 kg, what is the ten00l,gwf1 0sgkv 3 vwsision in the string? (Ignore friction and the mass of the pulley.)

  A student pulls a box of booksjihn(c2 w/jz:knr /; c on a smooth horizontal floor with a force of 100 N in a directi znk:whn c j2j/i;r(c/on 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 booksl;y 21mv(r ap09zqyro on a smooth horizontal floor with a force of 100 N in a direction of 37.0e above the horizontal. If the mass l 9a;yqv1z pm(yorr0 2of 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 shown in Figi1 ke+,3dh y/n z*gujg. 4-2. What are the tensions in thed/yz,3* h+gui1j ke ng ropes?

  In Fig. 4-2, if the tensions in the ropes are 50 N, whati.c*u m8kbnev)23 in k is the mass of the traffic li*2c n).8kunmve iib 3kght?

  Two boxes of masses m akf2t(vl 4(s6/u)ccwk mhpg.pnd 2m are in contact with each other on a frictionless surface. (See Fig. 4-3.) Wwuckv()62 tmk4 .cpg fh(/plshat is the acceleration of the more massive box?

  Two boxes of masses m and mv+ b9t2 re0pde,6xt9iggvn *2m are in contact with each other on a frictionless surface. (See Fig. 4-3.) What is the net force on the more massiveg+nib9mep6tr, tegvxv* 09 d2 box?

  Two boxes of masses m (to3ybt 9e 0cband 2m are connected by a rope. (See Fig. 4-4.) If the forward force on the more massive bocb0 to(ty93 bex is F, what is the tension in the connecting rope?

  Two boxes of masses m and 2m are co,mik5 zl5m1 -q vy3ax 7urpw6jnnected 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 massive bow ,73rl5 kaym5jxm6 zqv1-u ipx?

Two boxes are connected by a cord running over a pulley krpmsy( er63+ad:/ djk ph41d as shown in Fig. 4-5. Box I of mak/k +ddp6 ryea(rhd:jpm41 s3ss
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 betnc3y,,b wrpt.ween a 3.0-kg box and a desk artwryp 3,.,b nce 0.40 and 0.30, respectively. What is the net force on the box when a 15 N horizontal force is applied to the box?

  The coefficients of static and kineoz ;3 p(ms0d4i;r-rpvwsdy du9 ;jqi 9tic frictions for plastic on wood are 0.50 and 0.djd oru s3 miys;v-;d 90p (w4;rzq9ip40,
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 dir812x.dkn-c ga it6 dorection. It slows and comes to a stop with a constant accelerationc i r2 kddg-.n6oat8x1 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 hor b4vwh9h5jrk5 izontal surface is pulled by a 5.0-N force. A 3.0-N friction force retards the motion. What is the acceleration of the ohwhrvbjk9 45 5bject?

  A horizontal force of 5.0 N accelerat4ucdc2tiz)r x *n,2 aoes 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 given an initial spstmx z;, ;t pbu2q;kp-eed of 10 m/s. It slides 50 m on themsxp;q utb2p, ;;kt- z ice before it stops. What is the coefficient of kinetic friction between the puck and the ice?

  During the investigatiop.o/ 8mnt:1vgt ar swp+sg *6wimr +l*n of a traffic accident, police find skid marks 90.0 m long. They determine 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 c s:8 wopval .wp m/6g*r+gitstr1+n*mar when the brakes were applied.

  Two boxes of masses m and 3m are stacked. (See Fig. 4-6.) yb0wu8hn ) )) o2g ewv;o3yrzi 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 yv0);hu o8wy2 ie3owzb n)gr )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 surfaceg-ssv w1o-xi*f)c5*n 4oe c zdk/af1a 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- wx1* f koi)aecafgsn1cozvsd -/*54 box, what is the coefficient of static friction between the boxes?

  An object is on a frictionlessma8cd g(l3i) y inclined plane. The plane is inclined at an anglegla ymi(c3d)8 of $30^{\circ}$ with the horizontal. What is the object's acceleration?

  A 10-kg mass slides down a flat hill that makes an a gdgb cv.q,.-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 inclinedar-9n4q2iv4 -h qkl yq 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 pla,nk5. lal(md bne 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 constan o *1g.kn ul+ntq0o0qmt velocity of 6.0 m/s tluqq 0n1.ogk*o m0n+.
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 dojwd k0xb9 :1iiwn 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 roug).8 bb 7komkneh $37^{\circ}$ 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 attachjq0 z97/cu:*kvqqhbsj y)-q yeq0by jh)-7*jq:v c9qkzyqus /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 2nv0 zv2c82(l fsa0vkd ww(iqinclined plane tilted at an angle fzdikc0qvn8(w( sa0vl2 2 v2 wof $33.5^{\circ}$ 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 gradul - ::vx4fbsdveqe ;j/ally increased until the objec4flvbv/e;-xqs j d:e :t begins to slide. The angle at which this occurs is q. What is the coefficient of static friction between the object and the plane?