Which of Newton's laws best expla dj9i9rb +lr8 mcppp.7ins why motorists should buckle-up?

  When you sit on a chair, the resultant force on j/o28bt / hxl:cny+ fvyou is

  In the absence of an external force, a mov/lb8oy 7ry+a; x9q4j lc+voozing object will

  When the rocket engines on t08h 7wk94+vhffr3 cxyty8 ns dhe starship NO-PAIN-NO-GAIN are suddenly turned off, while traveling in empty space, the st38w8 79 yrsfhdxt0yfn4vc kh+arship will

  A rocket moves through empty space ;y+i -rp6sov zin a straight line with constant speed. It is far from the gravitational effect of any star or planet. Under these conditioniyor - ;6+spvzs, 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 suddenly fall d)boeyb- 7z+*t+j rmfforward. You can imply fr)bfm- b o*7 ydzr+tej+om this that the bus's

  You are standing in a moving bus, facing fo arwt gz6*)fo9/kyn0x phs. :3.izwmurward, and you suddenly fall forward as the bus comes to an immediate stop. What forcpygr tu.k 3* io 0wx6amz)z/fhw 9:.nse caused you to fall forward?

  A constant net force acts on an oe-s9d0 k77g l lm8wotubject. Describe the motion of the object.

  The acceleration of an object is ind.bb nmf y2,qgqi 8ums8 +4y/gversely proportional to

  A net force F accelerates a mass m with an acceleration a. If the samer yl)04-kzctt net force is applied to mass 2m, then the accelerationylctz)k0-r t4 will be

  A net force F acts on a mass m and produces an acceleration a. What actyy w/d:: ui*es g+vcp)8-zbo celeration results:uo*8 b y:y-/cizpvdg ew s+t) if a net force 2F acts on mass 4m?

  If you blow up a balloon, and then release iticya )io4fr jl(ud/3:, the balloon will fly away. This iji :o uicfl4/3rd(y)as an illustration of

  Two cars collide head-on. At every mom.uao 5z2ellkq rj031jent during the collision, the magnitude of the force 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 5r1k 2q.jllaoj3e0 zuan example of

  If you exert a force F on a8j2zuhn)m z1t n object, the force which the object exerts on you wim2hj1 uzt z)n8ll

  Action-reaction force j*/c2ul -f:byt, xuoys

  Action-reaction forces ar4,fr ongwau/-e

  A 20-ton truck collides witcx8. tc,hv gs-h a 1500-lb car and causes a lot of damage to the car. Since a lo,8scxhvc t. g-t of damage is done on the car

  An object of mass m sits o s)hwwv03(7evh;/wwkp2m k zun a flat table. The Earth pulls on this object with force mg, which we will call the actio3v0)v(e hkzww72 whmsw;u/pkn force. What is the reaction force?

  A child's toy is suspended from tub uz*iw0k.,a0;u jk rhe ceiling by means of a string. The Earth pulls downward on the toy with its weight force of 8.0 N. If this is thbu0 zjk0ai,w uu.k*r; e "action force," what is the "reaction force"?

  Your bat hits the ball pitched to you with a 1500-N instantaneous force. saskfn7vq7ks+o wgz6 +m4 3t- The ball hits the bat with an instantaneous+tks 43q+7 f-ngs7m s awv6zok force, whose magnitude is

State Newton's threeh7 z-.oa7i74wx r(dvuyk4cod yn 5dsir1.qu+ laws.

  Mass and weight

  The acceleration due to gravity is lower on the Moon than on Earth. Which of ddb2 i,;k5wr tthe foll5 bkr; id2dw,towing is true about the mass and weight of an astronaut on the Moon's surface, compared to Earth?

  An example of a force which acts at a distance z,q lxg 4zq/o)is

  Who has a greater weight to mass ratio, a person weighing 400 Nrk,wa n5hz o0/ or a person weigao z0rh 5kn/w,hing 600 N?

  A stone is thrown straight up. At the top of its path, thepadn3 :0v cur( net force acting on it isduaprvc0n: (3

  A 20-N weight and a 5.0-N weight a;- fb: v;voytd8hjy biq)2n ysib96;bre dropped simultaneously from the same height. -n; svb ; d:yvj;by9 yh8if6)oqtbi2bIgnore air resistance. Compare their accelerations.

  A brick and a feather fall to the earth at their ai z9 noxo,jml3f)0: h9y4qmxrespective terminal velocities. Whichml9xnoi mq, x9ja:z0o)34fhy object experiences the greater force of air friction?

  An object of mass m is hanging by a str7wdy z.srze,3/cr-n0, lc o;g:vscm v ing from the ceiling of an elevator. The elevator is moving up at constcvyv :rd;w3rceg/0cl,.,z-z s sno 7mant speed. What is the tension in the string?

  An object of mass m is hanging by a string from the ce2vza )wx p3j1ziling of an elevator. The elevator is moving upwarzap 2jxz3w) 1vd, but slowing down. What is the tension in the string?

  The force that keeps you from *r3pw9x+29il1z af(ni zqf k qsliding on an icy sidewalk is

  It's more difficult tce6p4o q rk:k2o start moving a heavy carton from rest than it is to keep pushing it with constant velocity, b:k er4qok62 pcecause

  A horizontal force accelerates a box from rest across a horizontfsf ;pv*t2pa5al surface (friction is prespa 52fs*tv;pfent) 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 slidajj97sgcz p7h6 tw6nul7elkn-hz4) .es down an inclined ramp at constant velocity. Thus we can z 7g-6hkn47z6 ulhl .jtc9pn j) a7ewsdeduce that

  A block of mass M slides down a frictionless planeyn f8grej p):3 inclined at an angle q with the horizontal. The normal reaction force exerted 3gr j)8:yfenp by the plane on the block is

  A block of mass M slides down a frictionless plane inclined at an angle qz9gj4q *jyc2y with the hori jgyz4 9jy2*qczontal. The normal reaction force exerted by the plane on the block is directed

  A block of mass M slix j5 a* 4rqu.oev*aqn/des down a frictionless plane inclined at an angle q with thx q*joqv/.un5ea4r a* e horizontal. The gravitational force is directed

  Two toy cars (16 kg and 2.0 kg) are rele-s2j6yx hepxi2r-up 3 ased simultaneously on an inclined plane that makes an angle of 30e with the horizontal. Make a statement which best describes their accelerxu3p6x2shp-y-r2i ejation after being released.

  An object sits on a frictionless surface. A 16-N 88;2d(t p ,q+hun xybg3yvd xxforce is applied to the object, and it bpudx2nyt +y;8d,h(x 8qg xv3 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 7.0 s. Wha9q cjok,naukr(3kwz.g sf2,2 t is the average forwaurnk ,qcgs2 kwakz3of,.9 2j(rd force on the car?

  Starting from rest, a 4.0-kg body reaches a speed of 8.0 m/s in 2. e3y,1q5dgc yj1b: cly0 s. What is th 1clq1,y cb35ygj:yede net force acting on the body?

  An antitank weapon fires a 3.00-kg rocket which acquires a speed oi8d 1tc2/5igom 6wragqz iz0-f k q:k0f 50.0 m/s aftdif/ztazo 8: kcq10 i2-q6kr50ggw mier 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 from1p2l 5h9h nlwz rel zp29l whn1h5st,

  What is the mass of a person who weighs 110 lb+4u.zoiidmutov 87l * ?

  What is the mass of an object that e8b*e8 j *u4 ynesfo3jweighs 250 N on the surface of the Earth where the acceeej8*4 y*njobe3f us8leration due to gravity is $9.80 \; m/s^2$?

  An object has a mass of 60 kg on the Ear* kk e,8qpr9zq8)ws/6* eow ktwnqqk-th. What is the mass of the object on the surface of the Moon where the acceleration due to gravi kk rqk8 qqn*qwek/t ws9o,*p)-6ze8 wty is only 1/6 of that on the Earth?

  Object A weighs 40 N on Ear oj hv3)qw9c(qth, and object B weighs 40 N on the Moon. The Moon's gravity is one sixth of Earth's. Compare the masses of the objects.oc3j h9wq(vq)

  Sue and Sean are having a tug-of-war by b*1 +fjo oide(3q hbwq3 vff.4 2uobc+pulling on opposite ends of a 5.0-kg rope. Sue pulls with a 15-N force. What is Sean's force if the rope accelera do. (3b2ecjov4f3f1obib w uq++h qf*tes toward Sue at $2.0 \; m/s^2$?

  A stack of books rests on a level6q1 hp qr.uq;3ym 6pq90 nw mv+yaz.uy frictionless surface. A force F acts on the stac6qn m.y3+u.qqvqy1h 0 w 6am;yzu pr9pk, and 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 stands on a scale in an g;i 9th(y2vi4j. ja(et4i) r+k byeimelevator. What will the scale be reading when the elev2m +ke(taj ti; igii).y4 eh4 bjyr(v9ator is accelerating downward at $4.00 \; m/s^2$?

  A person on a scale rides in an elevator. If the masf;nu;jcj((b te p-.ibx t1jv7s of the person is 60.0 kg and theb.nvju(;c1 pbfije7 xt;j(-t 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 elevator. If m6e66a bqxf3 fbgmg;z1 g7wv0 the mass of the person is 60.0 kg and the elevato76f6q6g fm w 3b;z 0gea1mgxbvr 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 x-w/o1lgr*xhmass. One force has a magnitude 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 agx*x-wo/hlr 1 cceleration of the mass?

  An object of mass 6000 kg rests on the flatbed of a truck. It is held i-h;hsoudl(i b.k1j tucs(b-* n place by metal brackets that can exert ah b -*1t(ksdsobli.juu-h c(; 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 res: i sdwuss6tw-i7x4l7ts 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, what is the minimum stopping time if the load is not to slide forward lu- x7isisswd6 :74wtinto the cab?

  In the Atwood machine shown in Fig.2tbrgyr932 m q 4-1, if M = 0.60 kg and m = 0.40 kg, what is the magnitude of the acceleration of yrb qr2gm3 t92the 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, wb+4d0 nktc2y, 8hv ohihat is the tension in the string? (Ignore frich0oh8 ybtk4dnci+ ,2 vtion and the mass of the pulley.)

  A student pulls a box of books on a smooth horizontal floor with a u/(ofaup 8f2p force of 100 N in a dirfp(o 8/ upu2faection 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 3oakw 02- me:c0hd-1 tbiw fhxsmooth horizontal floor with a force of 100 N in a direction of 37.0t c3h 2wxwk00oei-bf-d1 :ahme above the horizontal. 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 100 N is supported by two ropes as shotyule* 3w0jz9qx 3n g22,5nv qksbi0zwn in Fig. 4-2. What are the ten3v0n35z2qkngl t 2wbq ,9*yzsx0eiju sions in the ropes?

  In Fig. 4-2, if the tensions in the ropes *a(4 i.fa8zwb5q.skk8 a tyndare 50 N, what is the mass of the traffic liga kd zn4q5yw saf8t*i.(b.ka8ht?

  Two boxes of masses m andxgrg)+k9 wur :.e4bss 2m are in contact with each other on a frictionless surface. (See Fig. 4-3.) What is the acceleration of the more massive b)ub9 srs exkg 4w:+gr.ox?

  Two boxes of masses m and 2m are in contact with each other +upia2;q6 rtq vq89jyon a frictionless surface. (See Fig. 4-3.) What is the net force on the more massive bo i2 jq9u;v q8p+tray6qx?

  Two boxes of masses m and 2m are connected 9+ec6qk0h qbg/5n 2 xvqr1ia wby a rope. (See Fig. 4-4.) If the forward force on the more massive box +rg/6wvc qxq i0b5 n2aq1k9ehis F, what is the tension in the connecting rope?

  Two boxes of masses m and 2m are connected by a rope. (See Figfgs3sv o4: i+7y by7agpo+kk) . 4-4.) If the forward force on th3 vskbok :yg77+f4gpao ys) +ie more massive box is F, what is the acceleration of the less massive box?

Two boxes are connected by a cord running over a pulley as shown in Fig. 4-5. 5mxxfglm(zw2 /*f,gx Box I of m(z 5fg*wm2 fmg/xxxl, ass
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 between a 3.0-kg box a;ykqn*, ep0u8)n4 7au 8qu,ogklaueqnd a desk are 0.40 and 0.30, respectively. What is the net forcen 8 uqn qe*8 )u,p0a u47ekqyklga;u,o on the box when a 15 N horizontal force is applied to the box?

  The coefficients of static and kinetic frictjsv1gdoeh:) 7 13r sntions for plastic on wood are 0.50 an7o) 3 hstr1gdj1nv se:d 0.40,
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 direction. Ipu x; 89q9z:bpygddptr 0qc5.t slows and comes to a stop with a constant accu: 9qxp p.; 8cb zydd950tgprqeleration 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 horea(q4v x)mezo60bgxs, (c 0paizontal surface is pulled by a 5.0-N force. A 3.0-N frvox 0ag 0c4b(peae 6 q,zms(x)iction force retards the motion. What is the acceleration of the object?

  A horizontal force ofctcqsh 4r, 0)x 5.0 N 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 initialxka 9ms95jo:icf (w j:fs6pp3 speed of 10 m/s. It slides 50 m on the ix(3f:c 6mjpskipw:99 o5 asj fce before it stops. What is the coefficient of kinetic friction between the puck and the ice?

  During the investigation of a traffic accident, +h4g-4wxu lxqpolice find skid marks 90.0 m long. They determine the coefficie4-xghlu4wqx +nt 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 areb z lm( 3a0cnv3kb1b:s stacked. (See Fig. 4-6.) The surface between the more masn33s(a 0klzcb: vb 1mbsive 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 spgc3(j/a (9pi ror z,itacked. (See Fig. 4-6.) The surface between the more o(a prrji 3,zc( /pgi9massive 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 friction between the boxes?

  An object is on a frictionless inclined uh )nl5isi:7(zq cg b,plane. The plane is inclined at an angle o)u:z q,(c5sln i7 bighf $30^{\circ}$ with the horizontal. What is the object's acceleration?

  A 10-kg mass slides down a flat hill that makes an anstl8tq.:vwqc0 q1v edd) z2,igle of $10^{\circ}$ with the horizontal. If friction is negligible, what is the resultant force on the sled?

  A mass is placed on a smoo de4k5/t-knf kth 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 inclined plane tilted at )ysgpnjm +5ny *x3 en7an 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 constant zba1i;82;sl-.al fyq)y kzdc +jr 5qdvelocity of 6rdb+y zc-kd 2;.) zaqilf y; sa5lq81j.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 mass2(l 1gze/, d gz.zygev m 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 mas)xwm( 5h hf.m 9jxcit*s m slides 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 r4cx5*whg h.y prk(2l+vrt:g wough surface. The cable attached to the log makescyg(t.h rvg5 ww r* px42k:l+h 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 qw6di1o pa9d f0nsr 7z90 srh9in h(v-plane tilted at an angles davzh q0s (7hnnr0i9f16rp9w 9i o-d 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 shi0* 5q qyk6sd8gw*iinclined plane. The angle of incline is gradually increased until the object beg*g 5q kwqi0s hs*8iy6dins to slide. The angle at which this occurs is q. What is the coefficient of static friction between the object and the plane?