Which of Newton's laws best explains why )ss*+euoj;n mqk m 2-s aj+)kimotorists should buckle-up?

  When you sit on a chair, the resultant force on you isw gxfj++f3rq5y i77my

  In the absence of an external force, a moving ob) wn yc7w/,lqlr/69jbsx 3dfgject will

  When the rocket engines on the starship NO-PAIN-NO-GAIN are suddenl2:7 lt/xv- q*wtx /:qy9met1whmwmrby turned off, while traveling iwmm /w9w2q:x:t/hrb t l vym1-*7 texqn empty space, the starship will

  A rocket moves through empty space in a straight line with consh,)ct b62e :xogm,r pltant speed. It is far from the gravitational effect of any star or planetxco:e g2p,tr)6m hbl ,. 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, facing forward, and you s aav35vjo hy;;od j:b6uddenly fall forward. You can imjavdjo;;v3oha 5 b6y:ply from this that the bus's

  You are standing in a moving w-:q supzy0/ kbus, facing forward, and you suddenly fall forward as the bus comes to an immediate stop. Whatsp-z:k0 wuq/y force caused you to fall forward?

  A constant net force acts on an obj cvx; if0uk-atm( vo ;c+.kndij,c; w-ect. Describe the motion of the object.

  The acceleration of an 3ju6q91du. vkfp3 nriobject is inversely proportional to

  A net force F accelerates a mass m with an acceleration a. If the same n vm6okz,.n8z; 0b frzeet force is applied to mass 2mm;vk.8 zn0,o6re fzzb, then the acceleration will be

  A net force F acts on a mass m and produces an acceleraitg,o yavrfp l 7l/jc 2f-*20ition a. What acceleration results if a net folily-r t72f2gopfv c*aij, 0 /rce 2F acts on mass 4m?

  If you blow up a balloon, and then release it, the ballwty, tmd.nj )+oon will fly away. This is an illustmnty .t+)w,jdration of

  Two cars collide head-on. At every moment during the collision, the magnitud)d/h9lnzh lbxw6o (l,e of the force the first car exerts on the second is exactly equal to the magnitudezn( dwl9h/ ,lh 6)oxbl 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 exerts on qxlh,s)5x3a qyou will,xa qhls xq)35

  Action-reaction forcesmfp7 *nxf5)qyjhxn 6/

  Action-reaction forces :l 3pf d,c5ph :4qwyuvare

  A 20-ton truck collides with a 1500-lb qk.+q .p;gwulmm+d p+car and causes a lot of damage to the car. Since a lot of damage is done+d plkwg mupqm. q;.++ on the car

  An object of mass m siyxd f+a(h .20fidz/ocf upeyq- *1jw- ts on a flat table. The Earth pulls on this object with force mg, which we will call the action force. What is the reaction ox*fyjfq +ha1d -.iyc euwz-(2/p0dfforce?

  A child's toy is suspejwl 9um;/ow 2pnded from the ceiling by means of a string. The Earth pulls downward on the tojlwp/;w9 m2u oy with its weight force of 8.0 N. If this is the "action force," what is the "reaction force"?

  Your bat hits the ball pitc,4 bf1d s(k2 vjpc*ncje9ls9bhed to you with a 1500-N instantaneous force. The ball hits the bat with an instantaneous force, w bfljbk d1*9se4svp(j,n2c c9hose magnitude is

State Newton's three lawsi7tw3h 3kin s*r7hm;m.

  Mass and weight

  The acceleration due to gravity is lower on theb xxld9 i,8(vq Moon than on Earth. Which of the following is true about the mass and wev ,qxl 8bdix9(ight of an astronaut on the Moon's surface, compared to Earth?

  An example of a force which acohjc.s i ka7((5d qk)qts at a distance is

  Who has a greater weight to mass ratio, a person weighing 400 N or a person we:dc - yqo9/vd z;o1bbgighing:vq-d1 d;o/yg9bcbz o 600 N?

  A stone is thrown straight up. At the top kcgkl/bo3 /1sof its path, the net force acting on it gsbc3ol /k/1kis

  A 20-N weight and a 5.0-N;*p r4qtm qxz ez c*c, 4tf-tlzv(:s5e weight are dropped simultaneously from the same height. Ignore air resistance. Cqr*vz*;z4q4pmt e,5zx f l -ct(s:ec tompare their accelerations.

  A brick and a feather fall to the earth at their respective terminal velocitievp-htuc/ g 6s8s.,b d2mxr8jns. Which object expers,tnrm p2.86g8vjh bs- /uxc diences the greater force of air friction?

  An object of mass m is hanging by a string from the c5bwoc8+gjqe1hrjhhg7 45 2h qeiling of an elevator. The elevator is ghej ohw5r7 42cghbh5 81 jq+qmoving up at constant speed. What is the tension in the string?

  An object of mass m is hanging by a string from myro*apo hh(117 xoo4 9po odzh75lx )the ceiling of an elevator. The e)9l1 y4oa pdoo7hmp*xo5h (o1xho7zr levator is moving upward, but slowing down. What is the tension in the string?

  The force that keeps you from sliding o47ozc s as5,c 02ajypcn an icy sidewalk is

  It's more difficult to start me4m:nwh w2o )x2wxzz(,kj.7 jmanl7 pi 8hml)oving a heavy carton from rest than it is to keep pushing it with constant velm 4wk :njjzhwh,l8ime7l zaom2 )x( )w .7n2pxocity, because

  A horizontal force accelerates a box from rest across a horizontal sur hh-ae7;+ ktdoddi 8 x3l+2ujcface (friction is ;ka+d37ux8 t 2h+o h-cded jilpresent) 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 acceleration?

  A packing crate slides down an inclined ramp at constant vecnn8ll47f ;;ulbk 07;o safaglocity. Thus we can deduce a4kn07;7llfgfln8 ;usbc ;ao that

  A block of mass M slides dolq3+ 3ga-i0rnhk: po iwn a frictionless plane inclined at an angle q with the horizontal. Thlk0hai-:3 +goi3qp rn e normal reaction force exerted by the plane on the block is

  A block of mass M slides down a frictionless plane inclined at an angle qphf cv689nhshqwj 7;dw23 1eb with the horizontal. The normal reaction force exerted by the plane on ;n1 qp 3webvs2c hjhd78h9fw6 the block is directed

  A block of mass M slides dot7bk ba; wd40iwn a frictionless plane inclined at an angle q with the horizontal. The gravitational force t b ai4;w70dkbis directed

  Two toy cars (16 kg and 2.0 kg) are released simultaneously r ntva-ov3.-q on an inclined plane that makes an angle of 30e with the horizontal. Make a statement. ortv -q3n-va which best describes their acceleration after being released.

  An object sits on a frictionless surface. A 16 yjr9go3zm 1u* g8fc+t c.m,cg-N force is applied to the object, and it accelerates gm9o+f1cm,y3gu c8*ctr jzg.at $2.0 \; m/s^2$. What is the mass of the object?

  A sports car of mass48wa dnwfp- /k 1000 kg can accelerate from rest to 27 m/s in 7.0 s. What is the average fk84n f-ad/pww orward force on the car?

  Starting from rest, a 4.ycqn wsubs1x3egv0 e1gt5 9ti+ f *3.d0-kg body reaches a speed of 8.0 m/s in 2.0 s. What is the net force acting on tng iut*3e0xegsw 1d.yt5s9 1q f+vb3che body?

  An antitank weapon fires a 3.00-kg rocket which ach)0 x4tzodw5 j czq 2;w3;nwzcquires a speed of 50.0 m/s afternwt0ow5h)zc dzc24; ;3q xwzj 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 m8xr os:qtq2 br/ 3*gc;llzdp*tyd .u 4ass with the same force that you push a 10-kg mass from resd tpucgl2 zx3:8s4y/*b tdlq;* roq. rt,

  What is the mass of a person : ey y./avcq9cxw5c0ywho weighs 110 lb?

  What is the mass of an object tha jrwa :a:eot8h(vd/:l nw )6pmt weighs 250 N on the surface of the Earth where the acceleratira)/6eoa l:: hww8t:mj(dn vpon due to gravity is $9.80 \; m/s^2$?

  An object has a mass of 60 kg on the n7--cwf:gmmg Earth. What is the mass of the object on the surface of the Moon where the acceleration duen7:mgcg w f--m to gravity is only 1/6 of that on the Earth?

  Object A weighs 40 N on2 35+ltv)n- u bvuqjam Earth, and object B weighs 40 N on the Moon. The Moon's gravity is one sixth of Earth's. Compare the maq lu 5t+vnv-abm3j2u)sses of the objects.

  Sue and Sean are having a tug-obvdr 7;1l vq5u7 hegyn2xx- x(f-war by pulling on opposite ends of a 5.0-kg rope. Sue pulls with a 15-N force. Whal;r uyv qxxg7xb-1d5h(2nv7e t 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 for:pe :y- s5wr1dye4/ 1qmiofyoce F acts on the stack, anq oo:-s514e1 pyd /fw:miyyerd it 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 s9am sz+p8 6iistands on a scale in an elevator. What will the scale be read+s8i z9psa6mi ing when the elevator is accelerating downward at $4.00 \; m/s^2$?

  A person on a scale rides in an elevator. If the mass of the person ubdh)6m3 k:hs)6 tzxopg 8op9 is 60.0 kg and th)md 6bso 8ztkhox )u96ph3g:pe elevator accelerates downward with an acceleration of $4.90 \; m/s^2$, what is the reading on the scale?

  A person on a scale rides in an e51l u,k .iijc -5rfsnolevator. If the mass of the person is 60.0 kg and the elevator accelerates upward with an acceleiulc5 .frk, join1s5-ration 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 of 8)xqert/x/3q v6d on,a.0 N and is directed due north. The second force toward the east has a magnitude ofoqer3 6)vndxx, /qt/a 6.0 N. What is the acceleration of the mass?

  An object of mass 6000 kg rests on the flatbed of a trucq sj:6d1wokkfjviw86 4 ;u:e bwr07a vk. It is held in place by metal brackets that can exe4;ew j8uk1 7qw v afosi:j kvr:6db60wrt 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 flatbed of a te rp99(d fip.sog:4s oruck. It is held in place by metal brackets that can exert a maximum horizontal force of 9000 N. When the truck is tr4e sg(9ppsfi o 9:d.oraveling 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, ifnjm kovb )+45r;hg -i wrts8u3 M = 0.60 kg and m = 0.40 kg, what is theo+ 8is 5u w-krg4tn)3mb hjv;r 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 = 0.60 kg and m = 0.40 kg, wd9 .odc0u9qm-ock 0e hhat is the tension in the string? (Ignore friction and thoc9.mqc0e o0dhu-d 9k e mass of the pulley.)

  A student pulls a box(4hdr( ,/6eqgykg x bq of books on a smooth horizontal floor with a force of 100 N in a direction of (yrd q6hg, kq(xge/ 4b$37^{\circ}$ 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 oknb.( )ofn5 dyf books on a smooth horizontal floor with a force of 100 N in a direction of 37.0e above the horn.f(o) kbndy5 izontal. 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 1pij u0o220q iv00 N is supported by two ropes as shown in Fig. 4-2. What are the tensions in the ropes?jou0v2q0ipi 2

  In Fig. 4-2, if the tensions in the ropes are 50 N, what is the mass ofzl p v::r0f1v* )(cw oelu:zyf the traflflpcwz*o1u fve 0:r v(::z) yfic light?

  Two boxes of masses m and 2m are in contact with each other on a fricti;y hbz*9mqnu2 onless surface. (Squm 92n;y*z bhee Fig. 4-3.) What is the acceleration of the more massive box?

  Two boxes of masses m and 2m are in contact with each othpj:fc qf :hc -8sl. midz2ni;zud.x 9)er on a frictionless surface. (See Fig. 4-3.) What is the net force on the more massive box?plcmc:n h.fs8qj 2z zx):9 ;ifd-i.ud

  Two boxes of masses m and 2m are connected by a ropes5tj92x bjxj *. (See Fig. 4-4.) If the forward force on the more massive box is F, what is the tension in the conne*j9j xb js2x5tcting rope?

  Two boxes of masses m and 2m are connected by a rope. (See Fig. 4-4.) If the fsc *k(;ic(/li b)fss porward force on the more massive box is F, what is the acceleration o ils;*ik((fc)spbs c/f the less massive box?

Two boxes are connected by mpso(gn q;:-udxwj3)q/i) caa cord running over a pulley as shown in Fig. 4-5. Box I of:wdqjsi) cm/;p-)g a un3q (ox 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 fric;oj oq9zz uuc ; jlnr:yg;(w80tions 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 is applied to 0 l;:gc89 u(norzojuzq;jy ;wthe box?

  The coefficients of static and kinetic frictions for pla .bd-alxl+t+x s+8ihs stic on wood are 0.50 and a+-l 8sb. xdx t+hil+s0.40,
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 thg nj lrtiw:d77yq(. s3e +x direction. It slows and comes to a stop with a constant acceleration of -w:s (i3gjr y tn7l7d.q$2.45 \; m/s^2$. What is the coefficient of kinetic friction between the object and the floor?

  A 10-kg box sitting on a horizontal surface isd)l aycjyjtmlt 6rg*ok6 k;1bb-)w :6 pulled by a 5.0-N force. A 3.0-N friction force retaj ay6l bwjr66lgko d:bm)tc1kt*)-;yrds the motion. What is the acceleration of the object?

  A horizontal force of 5.0 N acceleratea q1xfkkjh-e 741i-cws 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 ig62mb wxdo8r/7 :dteqs 3e(fp nitial speed of 10 m/s. It slides 50 m on the ice before it stops. What is the coefficient of kinetic friction betweeqwo /3m8p:(gxb erde2tdf67s n the puck and the ice?

  During the investigation of a trafficoiex kr v1*d )ek9n8l7wqfe6jp c9g:; 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 car * 6;:eec7kkn edlgjov) q wr1 f98xip9when the brakes were applied.

  Two boxes of masses m and 3m are stacked. (Sekcuq a9/c9+ pge Fig. 4-6.) The surface between the more massc+gp/a 9cku9q ive 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 static friction force on the less massive box?

  Two boxes of masses m and 3m are stacked. (Se3bupe 0ro;wlje(. , jce 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 coefficient of static frictiope.3j(c;r o ljbwu,0en between the boxes?

  An object is on a frictionless inclined plane. The plane is incliwrihx2 hs)/-(v cbfvw(7i 4xe yv5( wined at an anglec2 wxwf vib7) /hs4 v(vr5(eyi w(hix- of $30^{\circ}$ with the horizontal. What is the object's acceleration?

  A 10-kg mass slides down a fi++a 8w-pm9a ya4 anrulat hill that 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 inclin qf.dj*j464;d uqzpzqed 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 pla5j7 evg7f .xzyne 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 di4 h.: hfkjjof*rectly down an inclined plane, at a constant velocity of 6.0 okj4ff:. hj*h 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 , ksys;7wc:rx 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)w l3-xz vwewsf 60hf7 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 ygqu8 vra,y6p5 3tpu)weighing 500 N along a rough surface. The cable attached to t pyt8pg5 u 6,aq)vyr3uhe 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 inclinedo8m;d- asdfp2 plane tilted at an anglefa;8 dmsdp2-o 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 on an inclin-zjutz05jq6a isy05c mj .yh*ed 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 coefficient of static friction between the objq-h ait0z jz6jcysu.5*0ym5ject and the plane?