Which of Newton's laws best explains why motorists should buckxl.:8nt.jgsw y en7q7 le-up?

  When you sit on a chair, the rep:t(f7ggys5 a sultant force on you is

  In the absence of an external force, a moving objj;8 nfrkdy5 zb :z,h*aect will

  When the rocket engines on thee qxstd6(ta4 bg 50l-f starship NO-PAIN-NO-GAIN are suddenly turned off, while traveling in empty space, the starshipgx fet-b l( at05q64ds will

  A rocket moves through empty space in a straight line wijd u hf1ygdkj9/j:- 2kth constant speed. It is far from the gravitational effect of any star or planet. Under these conditions, the force that must be applied to j/u yfjkk-: d9gh 12jdthe rocket in order to sustain its motion is

  You are standing in a moving bus, facing forward, and you s 8n(s)kolmr c0uddenly fall forward. You can imply from this that the bus'srks(ol0n )m c8

  You are standing in a moving bus, facing forward,v6sh53zeur);w, onxon kkxf6z30: chvy *;n n and you suddenly fall forward as the bus comes to an immediate stop. What force caused you to fall f;3vwe;5ho*sc)xh,u 6nnzk0:zor vnxn 3 yf k6orward?

  A constant net force acts on an object. Describe the mou :tt2v: w7oxation of the object.

  The acceleration of an object is inversec4vifscne- g8 -i/c c1ly proportional to

  A net force F accelerates a mass m with an acceleration a. If the same 8 8 5:alkq3cgk-jp ixme*yk.vnet force is applied to mass 2pqik8el*yjc .-xm8k 3 vagk5 :m, then the acceleration will be

  A net force F acts on a mass m and produces an acy6 ryeig1xnn0+j- s d9celeration a. What acceleration results if a net force 2F6-d sx0 1egi9yn+yr nj acts on mass 4m?

  If you blow up a balloon, and then release it, the balloon will 4b7 w53gv3 x4lo wmecac6h63imk /t jkfly away. This is an illusti m5 toh4 lwxjcw/a4 c m6k3e67b3g3vkration of

  Two cars collide head-on. At every moment during the collision, the +b hk +8c zk7siotc5,nmagnitude of the force the firsth +kk5n+c z,cb 87soit 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 ovamred(ann zlc 8/9ci/,1:a which the object exerts on you wi8a/9 c/1zem:aaod( n, lv rcnill

  Action-reaction forcep(u0-)k+ujtp c opjx 3s

  Action-reaction forces ust af 7 8-iozz;h):tqare

  A 20-ton truck collidel 8rt69rx:7:o xuwkmms with a 1500-lb car and causes a lot of damage to the car. Since a lot of dtr :9 m8mx6rx u:7kowlamage is done on the car

  An object of mass m sits on a flat table. The Earth pulls on this object wicrg1g )c i;qbr)0x nf2th forcebg2;fg)1rcc q r)ix n0 mg, which we will call the action force. What is the reaction force?

  A child's toy is suspended from the ceiling by means of ad82r1xho hj2n string. The Earth pulls downward on the toy with its weight force of 8.0 N. If thish 2drj28 nox1h is the "action force," what is the "reaction force"?

  Your bat hits the ball pitched to you with a 1500-N instantaneous force. The bwx) w tw5a/kln3,2gx wb . umbf:qt,u2all hits the bat with an instantaneous force, whose ma3q g:n 5wu w. ,fw)tm2b2x,l tub/akxwgnitude is

State Newton's three l7ts3mav4( mb8 yz/dmbwr7hk7 aws.

  Mass and weight

  The acceleration due to gravity is lower on the Moonn)jp q+ kvqqa pj yreh,) -fr/;:saw8. than on Earth. Which of the following is true about the mass and weight of an astronaut on the Moon's surface, compared to Earth?+ )qe q:- r8f)sj.hwp ,a/pvayr;kqj n

  An example of a force which acts at a diamn-az2z8t kl95g-v kstance is

  Who has a greater weight to mass ratio, a perso-jj+sjg i8v9 fn weighing 400 N or a person weighing 60 -9g8jj s+jfvi0 N?

  A stone is thrown straight up. At the top of its p6mi9c6fgp) 7/d9 i 4ugu;oxcwjhe/qx ath, the net force acting on itu/eohcwm9i 74qx u9/g 6cf6;pdg j)xi is

  A 20-N weight and a 5.09s;ue olp1pcl j;b 4vkficmb+/x*y - *-N weight are dropped simultaneously from the same height. Ignore air resistance. Compare their sm u**lbp/y+p9v1 ejlx;f cc- i ;ok4baccelerations.

  A brick and a feather fall/ hbkf -5u7zaa to the earth at their respective terminal velocities. Which object e5 bu 7hzaf-ka/xperiences the greater force of air friction?

  An object of mass m is hanging by a string from the ceiling of an elevator. 4kj;ckdv1e; iThe elevator is moving up at constant skvk i4;j;ec1 dpeed. What is the tension in the string?

  An object of mass m is hanging by a string from the ceiling of an elevlv)s 4i dlr:;vj(ox83nwh6: )x rtpdgator. The elevator is moving upward, buto t(lp:)dvds8wv rh;r3injx4) lx:6 g slowing down. What is the tension in the string?

  The force that keeps you from sliding on an icy sfwpehn u1dc .)-i)b8jsj (u /sidewalk is

  It's more difficult to start moving a heavy carton from1vei k+j y1.mrze6ob 3 rest than it is to keep pushing it with 6y.3ko e zbj1mvr1+i econstant velocity, because

  A horizontal force accelerates a box fr : :b+2 +wy uyreiin:.qmhsff0om rest across a horizontal surface (friction is present) at a constant rate. The experimentqb+w i20 +hufeyi:f:s nmy:r. 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 -84;atpja (xycnbj(o3q6j qy at constant velocity. Thus we can dnqyy( 6at(4j 8bj3xca-po ;j qeduce that

  A block of mass M slides down a frictionless plane inclined au6ls6 anq -ir*t an angle q with the horizontal.qil-sn* 66aru The normal reaction force exerted by the plane on the block is

  A block of mass M slides down a frictionless planed gj6ww 5z6aic7zp+.22mr znb ff;bf9 inclined at an angle q with the horizon9rmj+z6wf 252g.aiwpnz fzf76; dcbbtal. The normal reaction force exerted by the plane on the block is directed

  A block of mass M sliddpwty 7w k66 2z;xn6dtes down a frictionless plane inclined at an angle q with the horizontal. The gravitational foxpdzw2n6yw dtt 6 6k;7rce is directed

  Two toy cars (16 kg and 2.0 kg) are released simultaneously 34dm xufw11j ron an inclined plane that makes an angle of 30e with the horizontal. Make xmd34jfr1 w 1ua statement which best describes their acceleration after being released.

  An object sits on a frict;bu xougjpzk ;.t*p7 :6q+kcbionless surface. A 16-N force is applied to the object, and it accelkux*.ukqb;: cg;pp6z b7j+ ot erates at $2.0 \; m/s^2$. What is the mass of the object?

  A sports car of mass 1000 kg can accelerowj-zgs4 e0 w rwmih;p5;5,o oate from rest to 27 m/s in 7.0 s. What is the average forward force ogz5iw ,j;0owr m ;s5oo- 4hewpn the car?

  Starting from rest, a 4.0-kg body reaches a speed of 8.0 m/s in 2.0 s. Whata7d)5apuz*2wm :w apn is the net force acting zn2ap 5wm: )wduap7 a*on the body?

  An antitank weapon fires a 3.00-kg rocket which acquires a speed of 50.0 w dhhqdst)a;o,;teq;5 z1bxgh gu:15m/s after h 5q)1ued,b a:o;;1 5hgttw zsd;xgqhtraveling
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 y.a :g r.84q hqlv(hbaqou push a 10-kg mass from rest,g 4(a: bvl8.r hqhqa.q

  What is the mass of a persy: (pug wh 7:9(omcl q72rxf4awa/m h 8ckm;jjon who weighs 110 lb?

  What is the mass of an object that weighs 250 N on the surface of- nxboc3q , z(act9mcd6nq:/l the Earth where the accelerno9x:c,c qbnmct 3 6a(/z l-qdation due to gravity is $9.80 \; m/s^2$?

  An object has a mass of 60 kg on the Earth. What is the ma bpmh54vmc*.wwik-9d/3r pd ass of the object on the surface of th534mrd*b-pi wckh 9 .wp/amvd e Moon where the acceleration due to gravity is only 1/6 of that on the Earth?

  Object A weighs 40 N on 9 ugl2a8yaq-6x v5jjeEarth, 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.ea62q 9uvj-8y 5lx gaj

  Sue and Sean are having a tug-of-waw0 wyxs:kggd/d18z 4u r by 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 accelerates toward Su4gy0wu/18 dk:gzs wx de at $2.0 \; m/s^2$?

  A stack of books rests on a level frictionless surface. A force ;e5ejv2lbdq ; F acts on the stack, and it accelerates aevb ;d5qjl2e;t $3.0 \; m/s^2$. 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 oi b*,1 *yzjh xjqfu3t4n a scale in an elevator. What will the scale be reading wujx3j1*z 4tbq ,*iyhf hen 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 pj,tw7 nx+t7ws erson is 60.0 kg and the elevator accelerates downward withj 7n7stxw+ ,wt an acceleration of $4.90 \; m/s^2$, what is the reading on the scale?

  A person on a scale rides *.xz (eyg/arnin an elevator. If the mass of the person is 60.0 kg and the elevator accelerates upward withy ag*(.rx/zen 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. dsbh0ncn , r6.7 * 3 hx(ke 1cdc0zi2xzlkj*hiOne 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. kcckbj2 liz ndx,x3 01.se dzh*n 0h(*hci67r What is the acceleration of the mass?

  An object of mass 6000 kg rests on the flatbed of a truck3pnni w/qe( u-s*k kzr05 st2x. It is held in place by metal brackets that cannew-r 5ks/3q*pxtk2su( 0 niz 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 6000 kg rests on the flatbed of a truck. It is held in p(zyv7 sua *,6bpx /.mzts;kcilace 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 sbiz;t s/ 6cpxk m(.vu7 s*,zaylide forward into the cab?

  In the Atwood machine shown in Fig. 4-1, if M = 0.60 kg and m = 0.40 7216u jjxgiur d-w:kk kg, what is the magnitude of the accelerati1-i ukr7ju:g xk26jdwon of the system? (Ignore friction and the mass of the pulley.)

  In the Atwood machine shown in io 8d7o-l8gz dFig. 4-1, if M = 0.60 kg and m = 0.40 kg, what is the tension in the string? (Ignore friction an7lod8izdg o -8d the mass of the pulley.)

  A student pulls a box:mt k1/k)c:sh dtdm+k of books on a smooth horizontal floor with a force of 100 N in a diretmm/k+s :t 1kkcd)dh :ction 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 aklf n4zmwba6s (4 j-(x smooth horizontal floor with a force of 100 N in a direction of 37.0e above kmf jsbwan(6z4lx (-4 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 shown in Fig. 4-2.(( xm cfxid0q0ol0z7x What are the tensi ifz7 0(xcmlqo 0(0dxxons in the ropes?

  In Fig. 4-2, if the tensions in the ropes are 50 N, what is the mass of the t74d3yj wx 1bnbraffiw4jn 1xd7ybb3 c light?

  Two boxes of masses m and 2m are in contact with each other on a frictionl9qcr9ta:u1qe-i:mregr 88 oyess surface. (See Fig. 4-3.) What is the acceleration of the more mass e r -miyqa:ur8grq9ct98:e 1oive box?

  Two boxes of masses m and 2m are in contact with each other on a frictionless s/ 4exqjtz gh5 3*k6-v*klcip curface. (See Fig. 4-3.) What is the nczh6kt lp*-4vex ijk 3 g5*/qcet force on the more massive box?

  Two boxes of masses m and 2m are conn7 ;;ezifrsq0 8aftpq:ected by a rope. (See Fig. 4-4.) If the forward force on the more mass;q ps7 :rfa ;fzi0teq8ive box is F, what is the tension in the connecting rope?

  Two boxes of masses m and 2m are connected by a rope. (See Fig. 4-4.) If tizvh shqk /rz1,t**r2he forward force on the more massive boxk h12rs,/v hzi*t q*rz is F, what is the acceleration of the less massive box?

Two boxes are connected by a cord running over a pulley as showc 9jo90 jgwic9n in Fig. 4-5. Box I of 99cw cg9i0o jjmass
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 kinetzods n*4g h;;xic frictions 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 appliedn;*gh4sx ;ozd to the box?

  The coefficients of static and kinetic fricth re.lp 97plhn*t:3a*wvo*vu ions for plastic on wood are 0.50 andl w:l***oph ra 7hevu.39ptnv 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. It slows and coq:hj8 8 +z8uhjbi(f ngmes to a stop witf8 ujhgh(j+ qnz8b i:8h a 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 horizonta(lqx13xs dej2f(- vwy gqabx 7x5n/ a7l surface is pulled by a 5.0-N force. A 3.0-N friction for-d( a 13v7gqxqj2fxlx75xs( nabe/ ywce retards the motion. What is the acceleration of the object?

  A horizontal force of 5.0 N accelerates a 4.0-kg mas 1mk uye/5t)aos, 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 speed of 10 m/s. It slidw8uz;9um9gwafe g* 9ses 50 m on the ice before it stops. What is the coe*w e9 wg9zgs;9fma8uufficient of kinetic friction between the puck and the ice?

  During the investigation of a traffic accident, police find skid marks 90.0 m defosd 32- 5wytg7qy (long. They determine the coefficient of friction between the cd w5 (tsyo7 fe-q2y3dgar'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.q5u.vuu8 kleq s;5w9y 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 e.qu us9;wk5uyl 58vqless 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 stackedbb duze+m97s 1*mic d4. (See Fig. 4-6.) The surface between the more massive box and the horizontal surface is smooth andisbu ddm9*e+bz1cm 74 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. T9tkjh8n0en/ x he plane is inclined at an angle one8k 9jh0tn/xf $30^{\circ}$ with the horizontal. What is the object's acceleration?

  A 10-kg mass slides dojp;nu**3egz*3 w nlaswn a flat 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 inclinzac 9bv8.; ulnz2r gzm 6x/n.ned 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 incllqquwff5hs4soo j92 uo -m.( 3ined 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 n bwt.rasp; 5 *+vwy bv;,5ywtsx ()6it6 lsfoan inclined plane, at a constant velocity of 6.0 w* bs )v,sto( .lprwb5 xyn6ti6w a5yv fst;+;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. vz1htdk6u1t6m l4 ef7 aj;db 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 doh3x1tn9dt n1ewn 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 surfacelrz9w7 +qqm0s. The cable attached to thel790 sm+qrwzq 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 res : ;cukr0.ddcft on a rough inclined plane tilted at an angle c0:k.;f dcdru 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 inclined plane. The angle of incline is gradual, q sxdph5i ld9)y;o/bly increased until the object begins to slide. The angle at which this occurs is q. What is the coefficient of static friction betweedd)ihbo,l;y/ sp5 q9x n the object and the plane?