Which of Newton's laws best explainsev/;of -6 dn-oxs je)d why motorists should buckle-up?

  When you sit on a chair, the resulta:e45 wxcwql) nnt force on you is

  In the absence of an external forctt0nz p( dqr0f/cxd6) e, a moving object will

  When the rocket engines on the starship NO-PAIN-NO-GAIN are suddenly turned ofjwvl.r f6m6s) f,svr.6 6jlfw m) while traveling in empty space, the starship will

  A rocket moves through empty scr54ze2o28 qyq gnvg ,pace in a straight line with constant speed. It is far from the gravitational effect of any star or planet. Under these conditions, the force that must be applied to the rockegq42nqr,zegy vc52o 8 t in order to sustain its motion is

  You are standing in a moving bus, facd by27o6e p( 4wm*w ;a4rtfnvying forward, and you suddenly fall forward. You can imply fyr4 v2*pwtb6(o am7 ;4ywfdenrom this that the bus's

  You are standing in a movingy ;/vf); n(nqkfrrvuld350cw bus, facing forward, and you suddenly fall forward as the bus comes to an immediate stop; nw/;r3y0n)f 5 flcurvq(kvd. What force caused you to fall forward?

  A constant net force acts on an object. zs3su 0-ofpv c/fll /8 Describe the motion of the object.

  The acceleration of an object is inverljxwb /.9fne;sely proportional to

  A net force F accelerates a mass m withep(svty6( y wl,bklq(7ri* .x an acceleration a. If the same net force is applied to mass 2m, then the accelerati.x(wer(y,6 (7il pvtlyq sb*k on will be

  A net force F acts on a mass m and produc,ozrq 3jo3yb( e4r*qu es an acceleration a. What acceleration results if a net for3, y jurqrb4ozo (q*3ece 2F acts on mass 4m?

  If you blow up a balloon, and then release it, th-(a8 w ) te4jqkcvk5jge balloon will fly away. This is an i4-(kvg8kjj t qe)wc5a llustration of

  Two cars collide head-on. At every moment during the collisioo 14xlhu73 )izto a.hvn, the magnitude of the force the first car exerts on the second is exactlyi3oo .h1t7h) uxazv4l 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 whichpthf* jdma;6, wojp 4a+0l 8pshj+* we the object exerts on you wi0;oap j* aw4fpshth ,wjep6l+8 + m*djll

  Action-reaction forcesr fy4 m53kmtl)

  Action-reaction forces are8uu b,(tyq7 2g bu(g( nzhzf8m

  A 20-ton truck collides with a 1500-lb car and causes a lot of dam*.dea/lii4 jv ra n6)oage to the car. Since a lot of damage is done on the carin ao)jel64i.r v/*da

  An object of mass m sits on a flat table. q xt*gts b5nov*ms; ,3The Earth pulls on this object with force mg, which we will call the action force. What is the rv3*o 5tx tq; sbm*sng,eaction force?

  A child's toy is suspended from the ceiling by7lc9; wn (by7tasbj9 tz a;oc+ means of a string. The Earth pulls downward on the toy with its weight force of 8.0 N. If this is the b n ba(9aotyt9zsw 77jl;+cc;"action force," what is the "reaction force"?

  Your bat hits the ball pitched d9to; tw 1y2.1sthm,l qh2t af+fiu-rto you with a 1500-N instantaneous force. The ball hits the bat with an instantaneous force, wotlf-;2dmyti,a9r sqfh12u+ 1. twht hose magnitude is

State Newton's three. v4gvfcbh,v( laws.

  Mass and weight

  The acceleration due to ges+ i,fw tvy xry8-h3 -+*smugravity is lower on the Moon than on Earth. Which of the following is true about the mass and weight of an astronaut on teyyur *iwh -v8xssg+f3tm+ -, he Moon's surface, compared to Earth?

  An example of a force which acts eaf7zk/9ef:lat a distance is

  Who has a greater weight t;: a ik vj:4js c5hu.)erix+xto mass ratio, a person weighing 400 N or a person weighing 600) .;uikxxjesv +5irt:ah :4 jc N?

  A stone is thrown straight up. At the top of its path, the net force d(c nrj :4xy,a (m*yznacting on c m4,r* najdz :xyn((yit is

  A 20-N weight and a 5.0-N weight are dropped simultaneously from the same hei(xsa -8 +trze yhv-sn0ght. Ignore air resistance. Compare their accelenyx +rv8-0(th zssea -rations.

  A brick and a feather fall to the earth at their respective teraxzhj.j0tf0-* 8*f.oh v qjd7i0emvxminal velocities. Which object *8. j7.ff oh- h*0dvxmaej jvqz0tx 0iexperiences the greater force of air friction?

  An object of mass m is hanging by a string from the ceilt s 2xuolgvqt4v.7ef/t1+ p,ling of an elevator. The elevator is moving up at constant speed. What is the tension in the strin tv4p/xl2gvq.+lt1e uosf,t 7 g?

  An object of mass m isx0)j7se5n g)xdi zn6s hanging by a string from the ceiling of an elevator. The elevator is moving upward, but slowing down. What is the tension in the stri)z xs s ndn60j7ei5)xgng?

  The force that keeps you from scc4gurd q67e3 liding on an icy sidewalk is

  It's more difficult to uxzud9p+ws+ aery,x t7y) 1d4start moving a heavy carton from rest than it is to keep pushing it with constds x +9 ewy)u47zpr1 xtyu+da,ant velocity, because

  A horizontal force accelerates a box from rest across a mb-rt. ml,b/u1yc 9zqhorizontal surface (friction is present) at a constant rate. The experiment is repeated, and all c1 mmu,/.9 z-tcqlbbryonditions 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,cor-:6y2d7+ il;w5uwy jlw lpb/yt h can ,cl-5rp/wolj:yy yli6+w72 th; du bw deduce that

  A block of mass M slid*wtu 2hiz1ip;2 6j qrdhxyi9*es down a frictionless plane inclined at an angle q with the horizontal. Th 9zpyii j2du2q1ritw6 *;h*x he normal reaction force exerted by the plane on the block is

  A block of mass M slides down a frictionless planemo4g,r2+h zqnp sr1 e0 inclined at an angle q with the horizontal. The normal reaction force exerted by the plane on the bloh0 eqm sz4+r,2g 1norpck is directed

  A block of mass M slides down a frictionless pvcvf jedwj r/ 6.1ee)/lane inclined at an angle q with the horizontal. The gravitatiojfv/6 )d . jewer1/vcenal force is directed

  Two toy cars (16 kg and 2.0 kg) are released simultaneously on an inclined 4cy 4cyj*v8x -vmtk0 kplane that makes an angle of 30e with the horizontal. Make a statement which best describes their acceleration ayc4c4y k*v x8jtv0m-kfter being released.

  An object sits on a frictionless surfj*72zxs:,wa i wn4ahs0)dlie ace. A 16-N force is applied to the object, and it accelerates atiw* 0i7 j2 ,e:wa4xhnld)szas $2.0 \; m/s^2$. What is the mass of the object?

  A sports car of mass 1us;m l.kmh: / zu3ss-7kjiyc 1000 kg can accelerate from rest to 27 m/s in 7.0 s. What is the average forward force on the carjcz-/7muh .:;iuy3s sk 1k lsm?

  Starting from rest, a 4.0-kg body reaches a speed of 8.0 m/s in 2.0 s. Whly yhzc :o)3pg9-7vtf at is the net forcy:f )y39v- hotl7zc pge acting on the body?

  An antitank weapon fires a 3.00-kg rocket which ac 4:cscvgcn/f+0fjf0e -c rpk5quires a speed of 50.0 m/s after travc4cck- rvgc pf:+fse 0fn/0 j5eling
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 n :5np60cg+f*eczae*n, tdjil r8v g3push a 10-kg mass from rest,z *v3gi*dr 0+5,ec 86a :tcngpjnle fn

  What is the mass of a persoqrq/b 4nj sx/;tf e2v/ pkr(d4n who weighs 110 lb?

  What is the mass of an object that weighs 2h9uy uav/f89j50 N on the surface of the Earth where the acceleration due to gravi/ 9ya8 uf9juvhty is $9.80 \; m/s^2$?

  An object has a mass of l a ob.hal;j((rggc 5hi;6eu6k:7ckj 60 kg on the Earth. What is the mass of the object on the surface of the Moon where the acceleratioig 7:g6ah ;krej c.cj(okull6ah5(;bn due to gravity is only 1/6 of that on the Earth?

  Object A weighs 40 N on Earth, and obj.)nnr-wm fyai fx4at56 ( mk;tect B weighs 40 N on the Moon. The Moon's gravity is one sixth of Earth's. Compare the masses of6fw5amn 4k(y).a x fnit;rm-t the objects.

  Sue and Sean are having a tugbtco7z7x z t;u+eb 2k iw;;v*+uzlf:m1 tm6pk-of-war by pulling on opposite ends of a 5.0-kg rope. Sue pulls with a 15-*w:mt7z+ ;om 2 xbvfz t+ b7i6u;k1ceu; zlptkN 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 force F act ehx9 q;oqghzrzq8b8/22.y1g u5kknps on the stack, and it acc8o5pkh/kzz;8qr 2h b21que xq.gngy 9elerates 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 srj c m;u,l0w j77:bhrrtands on a scale in an elevator. What will the scale be w0 jh:clrjm,r;bru77reading 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 vjhff 08 lnm53 tnc/y4fa7e8g)nzyw8the person is 60.0 kg and the elevator accelerates downward with an acceleration of tvy08fnahz8)efmncwj47ny g8/35 l f $4.90 \; m/s^2$, what is the reading on the scale?

  A person on a scale rides in an elevator. If thw:rg( -ynu 0nqsp j3q2e mass of the person is 60.0 kg and the elevator accelerates upward with an acceleratiorq20:nn wuj3y -qsg (pn 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 8.0 N s: -vg.8yhptk e5.cz yand is directed due north. The second force toward the east has a magnitude of 6.0 N. What is the acceleration of the masc8.htvy-y s.p kz e:g5s?

  An object of mass 6000 kg rests on the fla,; 2g7y6/ xu wetfhlyq3,vbpo.d g,yrtbed of a truck. It is held in place bvw l3,/2x.7gfuytobprd;6yyq, ,g hey 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 distance if the load is not to slide forward into the cab?

  An object of mass 60,u80 gnl4umk t00 kg rests on the 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, whamknu ,u8 l0gt4t 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 kgik6/ow 4nq7hx and m = 0.40 kg, what is the magnitude of the 4ow xkiq/7nh6 acceleration of the system? (Ignore friction and the mass of the pulley.)

  In the Atwood machinepi0f*5 w+6f iwdw /b -wsasrd7c3ng+r shown 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 mass ofrwsagdsdp+ nf w-36i/+7*5i wrc 0wfb the pulley.)

  A student pulls a box of books on a smooth horizontal floor with a force of 100 l qmn/y 0wdxa/ 5*0adxN in a direction om*ynq ax/w0a/lxd 0 5df $37^{\circ}$ 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 smooth horizontal floor with a forc 8 m6sgrp.jbv,e 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 is the normal force o.rm j8,6bgspvn the box?

  A traffic light of weight 100 N t yfu 4/0oq+ncc-8umc:c0ss j is supported by two ropes as shown in Fig. 4-2. What are the tensions in the ropes?8j mu-t fcc: cq4y0+/nosusc0

  In Fig. 4-2, if the tensions in theb3 :4( h q.jepenhk7tl ropes are 50 N, what is the mass of the traffic ligh j.:nqthkheb 4(37pe lt?

  Two boxes of masses m and 2m ara6i ;7 80wwah8 qpldlce in contact with each other on a frictionless surfacwa867 pqd8h;0lwilace. (See Fig. 4-3.) What is the acceleration of the more massive box?

  Two boxes of masses m and 2m are in contact with each other o57q yns xuwzk85i x0l9n a frictionless surface. (See Fig. 4-3.) What is the net force on th iq7zkn s805wu yl59xxe more massive box?

  Two boxes of masses m ar :-cblnie0onx5e. r,nd 2m are connected by a rope. (See Fig. 4-4.) If the forward force on the more massive box is F, w-0lecri: xb nnoe ,r.5hat is the tension in the connecting rope?

  Two boxes of masses m and 2m are connectedo gp;-m .(pggb by a rope. (See Fig. 4-4.) If the forward force on the more ;-gmbg (ogp.p massive box is F, what is the acceleration of the less massive box?

Two boxes are connected by a cord /yg c 4yg(ydk,running over a pulley as shown in Fig. 4-5. Box gydyg/4k( y c,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 as9v ( -e1uv ty)xzs+frnd kinetic frictions between a 3.0-kg box and a desk are 0.40 andx ryv(t)euv+1 -fs s9z 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 kinny6 p (x ufkovvpc9n 49g9bz4o+c- ;rsetic frictions for plastic on wood are 0.50 and 0.40f+xcvs4( u9y 9;ncvog4npkp-r6b9o z,
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 slows and comes tv(;yq)qq6xf 5ovxa m1 o a stop with avm;qyx 51vqf o 6q(a)x 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 force. A 3.0-ue 4xi-8rrrjuh9s /9yN/ie 8u-99hr rjxs 4ryu friction force retards the motion. What is the acceleration of the object?

  A horizontal force of 5.0 N accelerates a 4brg f,5l 0 0y2yawzj9y.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 iz,.y7e ze3gm r )hq-vvnitial speed of 10 m/s. It slides 50 m on the ice before it stops. What is the coefficient of kinetic friction betzzvyq e)me-,3 h .g7rvween the puck and the ice?

  During the investigation of a traffic accident, police find skid marqg ;, hzi)vec4ks 90.0 m long. They determine the coefficient of friction between the carvchi,4 g; qze)'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. nrv *mb)cmoj z,.we2( z(puw* (See Fig. 4-6.) The surface between the more massive box and the horizontal surface is smooth and the surface between the boxes is roc)u(ow(nb m e z w2.jm*,rz*pvugh. 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 anm-s64jvyvrgu :;+s nx d 3m are stacked. (See Fig. 4-6.) The surface between the more massive box and the horyr g;s xs+-vj:6u4nmvizontal 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 friction between the boxes?

  An object is on a frictionless inclined plane. The plane is inclined at an angldf0iz+dj :tm2e of :t2 fdid+zm0j $30^{\circ}$ with the horizontal. What is the object's acceleration?

  A 10-kg mass slides down a flat hill thano/2wudsu h: a inw 4)28mj-ikt 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 .u p .jk4vcaz*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 03o. deivj;g dq8 m9qzinclined 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, atn zwdlni6eo8 hbquv-b +;i* 6af 6:2ht a constant velocity of 6 v lt6b2deq owa;fhnz+:b- 6uhin 8*6i.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 a rough ; 7crjgnhq9 1+:fwoyx$37^{\circ}$ inclined plane where the coefficient of kinetic friction is 0.20. What is the acceleration of the object?

  An object with a mass m slideb 7rdjkj)y(q xo4jd0jusnho1 7l )5jmk9 1yn 3s 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 cableutn gi7,4k cjybp 7h7* attached to the log makes an ap*7 4k7nt7bugjcih, yngle 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 re2 quh zh)k*sw - tu+pts3;wn./ hy3nmxst on a rough inclined plane tilted at an angle of nhu;)sxz tt wu3+*-2whhqm/ny3.k sp$33.5^{\circ}$ 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 gradr4zhzz(avxpz 7; xp2t 32.q fiually increased until the object begins to slide. The angle at which this occurs is q. What is the coefficient of static friction between the object and 2.i(;axhrp z24 fpt3x vqzz7zthe plane?