Which of Newton's laws best explains why motorists should buckle-up?f: vt/ut6s*aq

  When you sit on a chair, the resultant force oj5+pu 5o 4(7ogkz5ksqha)p oan you is

  In the absence of anoh lo x. xy22fmufvbf :kbblb4..,f)1 external force, a moving object will

  When the rocket engines on the starsh7hj: tpzd 2f8rip NO-PAIN-NO-GAIN are suddenly turned off, while traveling in emptyf dthjp:z7r82 space, the starship will

  A rocket moves through empty space in a straight line with constant speed ;wtam9w xf*i7. It is far from the gravitati*9w7 mt;ax wifonal 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, fachdi4lyu.+nfc+d *u(y3s 9tzc ing forward, and you suddenly fall forward. c fz uh++.cy39n4 d *tsyliud(You can imply from this that the bus's

  You are standing in a moving bus, fz/f x-xgn3pbz(h c+f7 cgh j3/acing forward, and you suddenly fall forward as the bus comes to agc/fx/(b- cj nzhpx3zh +f37gn immediate stop. What force caused you to fall forward?

  A constant net force acts on an objec cik-6 oxn.g3mt. Describe the motion of the object.

  The acceleration of an object is inversely propor-iuv(z7vjs* / jsgbj0tional to

  A net force F accelerates a mass m with an acceleu:5gx bwkg5zz g* 6cwplj26 (2sbuk9pration a. If the same net force is ck bx6z jw2u2gg*9upbp5gwl6 :z s5 k(applied to mass 2m, then the acceleration will be

  A net force F acts on a mass m and produceql to+czp1;r- s an acceleration a. What acceleration results if a net force 21oqlpr+c-;z tF acts on mass 4m?

  If you blow up a balloon, and then release it, the bald/*pr ;3ez;qaud+k g y;ad0l9q/ vgxjloon will fly away. This is an illustr9d;+a ;qzjg/ l ueg/v;xq3k rdpa0y*d ation of

  Two cars collide head-on. At every moment during the collision, the magnitude te3bw7n(aed a9p( 9na of the force the first car exerts on the sa3tnaden(w(ea97 9b pecond 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 w5urwg p2h*pm nhv 8:3chich the object exerts on you willn8r5mp3uphg 2c:h*w v

  Action-reaction forced7i(6nr *n.+r (iznl; t uz8 ylvfeyd:s

  Action-reaction forces aird, +:hqs4q qre

  A 20-ton truck collides with a 15q( 5-gqh/x8s; jdsae( tss8x fvf*8pf00-lb car and causes a lot of damage to the car.t xsdp v( 8e-hjsf8fx(s 5*f;s 8agq/q Since a lot of damage is done on the car

  An object of mass m sits on a flat table. The Earth pulls on this f,/a7o5l jc89sjs ye0f+h i e/rqz:r uobject with force mg, which we will call the action force. r+ is/je0j/9 efc7yl8shfq ,uoar:z5 What is the reaction force?

  A child's toy is suspended from the ceiling by means of a striddys1vysgj)n ab77 z4z:2x5jng. The Earth pulls downward on the toy with its weight force of 8.0 N. If this is the "action4: n57ybvzgay7xdzsj) 1jd 2s force," what is the "reaction force"?

  Your bat hits the ball pitched to you with a 1500-N idwk1l ble99l1nstantaneous force. The ball hits the bat with an9 1wd9bk1ll le instantaneous force, whose magnitude is

State Newton's three ( -9v/u zdp)8e1ra9zd rlebjdlaws.

  Mass and weight

  The acceleration due1s7 emuk0.2ol m o+mkt to gravity is lower on the Moon than on Earth. Which of the following is true about the mass and weight of an astronaut on the Moon's surface, compared to Eak+u0.mo1tl emm7osk2rth?

  An example of a force which acts at a distance is/3;f5;w m tpwchn-tb f

  Who has a greater weight to mqxf00xsx lc-7 .x tco3j.qr: uass ratio, a person weighing 400 N or a person weighingxsj xo07c q l. u:0f.xrx-qc3t 600 N?

  A stone is thrown straight up. At the topnv v80 jyi 7y4xmtcw- udc,7.9m0osmj of its path, the net force acting on itmxv4t y9jmvid 8ujyc.o 0sn0 77cwm,- is

  A 20-N weight and a 5.0-N znvyuu:z i b*lu(1;-t weight are dropped simultaneously from the same heightnuz:ut;(lizyv u*- b 1. Ignore air resistance. Compare their accelerations.

  A brick and a feather fall to the earth at their rezd u0g a:ndo/fr7 crnh;*t vv xic00w +.ib.5gspective terminal velocities. Which object expf.i. a0bd5w:v;ctr n0vn7 /iz0r*uxco hg+d geriences the greater force of air friction?

  An object of mass m is hanging by a string from the ceili.1jdt* c fy8t; b/kqkkm0*n iong of an elevator. The el;qm/ k.tktfj8d c*1yk* b0noievator is moving up at constant speed. What is the tension in the string?

  An object of mass m is hanging by a string from the ceiling of an elevator. The20y lpjf*6hh ohw2fx- elevator is moving upward, but slowi hofjwlfxh0*- hp622yng down. What is the tension in the string?

  The force that keeps you from exz3,18 da:pbv , 1m3mzbyoipsliding on an icy sidewalk is

  It's more difficult to start moving a heavy carton from rest than it ic rzna)1b4wo+s to keep pushing it with constant velocic1+ab )zo rn4wty, because

  A horizontal force accelerates * io8 ,qc a lfd,*pf/wo4aa1kha 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 happei,qpak4 1ha8oad*/f cl wof,*ns to the box's acceleration?

  A packing crate slides down*-(ka,b5 v*wt lqmg/ d-hl jue an inclined ramp at constant velocity. Thus we can deducek a5m- -l(vwu, d* jlq*get/bh that

  A block of mass M slides down a frictm : p4r;plt/,6jiu9r; s+msotbpyw5qionless plane inclined at an angle q with the horizontal. The normal reaction force exerted by the plane on the blocw6rmos5b mu,9;jp t:t ip;yl+ /4qsr pk is

  A block of mass M slides down a frictionless ksoo.2 zk 9 -e1rrerh+plane inclined at an angle q with the horizontal. The normal reaction force exerted by the planz1es+hk9err o - rok2.e on the block is directed

  A block of mass M slides down a frictionless plane inclined at an angle q /1on5rcp5.gyog kb a ,with the horizopo.5gk cgnb5 a/ro1y,ntal. The gravitational force is directed

  Two toy cars (16 kg and 2.0 kg) are released simultanejce lz cao)0h40 2ui8mr0 hd.wously on an inclined plane that makes an angle of 30e with the horizontal. Make a statement which best describes their acceleration after bei)o08hhc zr2cu 0w.40e jmdali ng released.

  An object sits on a frictionless surface. A 16-N force is applied to jjr(.5f h:nhht px0.cthe object, and it accelera(h .5n xrp:jhjhtfc .0tes 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 2 qwut3 sip5n9e*4/vg v7 m/s in 7.0 s. What is the average forward force on the car?eq/wspntv9v5i3*4g u

  Starting from rest, a 4.0-kg body reaches a speed of 8.0 n bs )y-ozli2w *p71fdwp( ,gvm/s in 2.0 s. What is the n -(pbd1pfw,ys27zvnlig *ow)et force acting on the body?

  An antitank weapon fires a 3.00-kg rocket whicg9i9d)f cy s7xh acquires a speed of 50.0 m/s aft7 x)9ifcd y9gser 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 with the same force that you push a 10-kg mass ftq z;g--y5 cjy+l4-;sp;0za o c-xc cfjy+rdurom resdyy4op 0tjqac+g;u-cs cz -jflr+ -z5-c ;;yxt,

  What is the mass of a person who weighs 110 hm,ss3(k/rt l 8p zq,elb?

  What is the mass of twp6h4y6jar/ bqz9s -da6f r.an object that weighs 250 N on the surface of the Earth where the accelah46s 9 6trb dr6p-y/zfjwa .qeration due to gravity is $9.80 \; m/s^2$?

  An object has a mass of 60 kg on the Earth. What is the mass a*jv. uygsa*t+gg8j n+b2(nj of the object on the surface o(t+jbyg* .g u nsja28jgav* n+f the Moon where the acceleration due to gravity is only 1/6 of that on the Earth?

  Object A weighs 40 N on Earth, xti4) vyxt /6ptxkj95a46l s 6.zxpwband object B weighs 40 N on the Moon. The Moon's gravity is)xs6 pk94t6p 4iyjazt/lxxvb .t5x6w one sixth 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 5.lpy-8*y 6kb(x ) k9x/ucjip si0-kg rope. Sue pulls with a 15-N force. What is Sean'ylisu-kpj x*)icx6y / bp(k89s 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 actsydcue tj;3dfu r9) 67y on the stack, and it acd;ufy6 93 d) 7ceytujrcelerates 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 stands on a scale in an elevator. What will the scale eo7uu (( /wmsabe reading when the elevator is a (oe 7/mu(awsuccelerating downward at $4.00 \; m/s^2$?

  A person on a scale rides in an elevator. If the mass of the pers1:gg if e.r:dyon is 60.0 kg and the elevator accelerates downwaiyr. fge:gd:1 rd with an acceleration of $4.90 \; m/s^2$, what is the reading on the scale?

  A person on a scale rides in an elevator. Iiw;r 9,y7jc sx3*x;l-jaj)dnqyrw 0a f the mass of the person is 60.0 kg and 0rn ysqjwr,cxj) i7*9 y3wl;d-aja; xthe elevator accelerates 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 force has a magnitude of p0haaotu0362 fw,0 l-cz )2viziwjrk 8.0 N and is directed due no t wvol 0fuzhp,i6r302kc -0w 2zij)aarth. The second 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 flat)4)bpazakfy .nk n/2e lcna //bed 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 tf a.c4k )l n/n2 /zea/anybk)praveling 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 tru bzan t7lw0+z q))ly4fck. It is held in place by metal brackets that can exert a maximum horizontal force of 9000 N)zbytln f )4qwa7zl0+. 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 = 0.6ch)* bvqjmkat+28+ oe0 kg and m = 0.40 kg, what is the magnitude of the acceleratib+8)q o +*k emhvj2caton 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 andms* zt2* vwxovvv 27:t m = 0.40 kg, what is the tension in the string? (Ignore friction and the mass oztvw v*vomx7 v:2s*t2f the pulley.)

  A student pulls a box of books 9x5 no s/ y;.ftw*5 zuxn-fwalon a smooth horizontal floor with a force of 100 N in a directioa*-nln5/x 9w f;x yf5 w.zutosn 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 smooth horizontal floor wip- b, vw.6ug reb;bvcqx;uf .0th a force of 100 N in a direction of 37.0e above the horizontal. If the mass of the box and the bookv. pvr0bqucgu we;b .xf-; 6b,s is 40.0 kg, what is the normal force on the box?

  A traffic light of weight 100uxve d agfd*la.9-11 0ibsos*nh3/vy N is supported by two ropes as shown in Fig. 4-2. What ao dbs1h9 /.i130 vlfd vsau*ex*gny-are the tensions in the ropes?

  In Fig. 4-2, if the tensions in the ropes are 50 N, what is the ma9r 0soldlg9p .9zba d0ss of the traffic lighd a0pz rs bo0gl9d99.lt?

  Two boxes of masses m and 2m are in contaj/z 9 p2opoi)l2l 6wibct with each other on a frictionless surface. (See Fig. 4-3.) What is the accelerati pp) j2 /z9bo6li2wiolon of the more massive box?

  Two boxes of masses m and 2m are in contact with each other on a frictionle 4 s9nleazv:0 sv rvu65g hz29l//hxiass surface. (See Fig. 4-3.) What is the0iz ex6/9z 2sla/:rugah9 45l svvh nv net force on the more massive box?

  Two boxes of masses m and 2m are connected v:tx6nkp y::a by a rope. (See Fig. 4-4.) If the forward fo v6y:p: a:kntxrce on the more massive box is F, what is the tension in the connecting rope?

  Two boxes of masses m and 2m are conne 7lftb7hj7 7fxcted by a rope. (See Fig. 4-4.) If the fjlf7h77b 7xftorward force on the more massive box is F, what is the acceleration of the less massive box?

Two boxes are connected by :9:0ehwl0c 85kr gfv+ 5m,ywnobrsdpa cord running over a pulley as shown in Fig. 4-5. Box I ency5v5 odhwr8,r lgf+b 0wm:90ksp: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 frictions/o cvhfk42tcm/ dg.vo/ ed88r 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 appliekvrtg ooc/d 4h d.v/28e/m8 fcd to the box?

  The coefficients of sta0zog: v-fgrt+n;,aey tic and kinetic frictions for plastic on wood are 0.50 and 0.aetr+ ;yo:fv,z ng0 -g40,
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 n:7)iy ewu4sna level surface in the +x direction. It slows and comes to a stop with a constant7s4nw:uy) ien 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 horizonta/eq msj69,9 cd4mcfzs7ux0rul surface is pulled by a 5.0-N force. A 3.0-N friction force retards the motion. What is the acceleration of the ob6fju/9c q 9uxrdc4mz7 e,sms0ject?

  A horizontal force of 5.0 Ns,nkm66 ecz 05w ngr2tm,waq9 accelerates 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 ims0rr nj nn 7,10ksqw3nitial speed of 10 m/s. It slides 50 m on the ice befonwqs00sn1j7 n k m3r,rre it stops. What is the coefficient of kinetic friction between the puck and the ice?

  During the investigation of a traffic accident24 ,9k bjwq2yimqgea6, police find skid marks 90.0 m long. They determine the coefficient of friction between the c94qi beakg6 j2,m 2wyqar'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. 4-6.) rv))2buq np f* 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 bu *2n))bvrfqpox, what is the static friction force on the less massive box?

  Two boxes of masses m and 3m are stacked. (See Fig. 4 wxp4 in8 bz *irv3er6h0i*vdav 8xd00-6.) 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 staticvaip 6 v0*8d 0ni0xbrrw3vd4e*izh 8x friction between the boxes?

  An object is on a frictionless inclined plane.i).zrxsz q: zcv4 )d6b The plane is inclined at an angle oxsv 6rz :.d4q zbc)iz)f $30^{\circ}$ with the horizontal. What is the object's acceleration?

  A 10-kg mass slides down a flat hill that mak za())kkcz.-m xgb 3gbovq- yr1-fk b;es 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 smoovsb;b;/ eyu4 qth inclined 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 inclinedw ;7z1ltpkl) g 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 pla jy0b o4 nrbxi+w(1b0ane, at a constant velocity of 6.0 m rjbb 4iwob01ayxn+0(/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 roubjvz3y;z/ 3og4 rllh, gh $37^{\circ}$ inclined plane where the coefficient of kinetic friction is 0.20. What is the acceleration of the object?

  An object with a mass m slid.yvz p jl91ig,es 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 cu wa;4 2oi*+ 6g1eesf mrn-d7*mglhocable attached to the i2 6-a4ce*; hrmngum+o7degf1w sl o*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 frovh*eswcd,7k -1tfewjk +1)iwm rest on a rough inclined plane tilted at an angle of ewtf11c)j,k-ive 7+sw dwhk*$33.5^{\circ}$ 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 z pcbt,y+h4/ ngradually 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 4,/ptcy zhnb+and the plane?