Which of Newton's laws best explains why motorists should bucklet81q; leyt y yj1bg51p-up?

  When you sit on a chair, the resultant force od f5t6zii; j+mn you is

  In the absence of an externqrj( ,)ts eoi 7w;:ceoal force, a moving object will

  When the rocket engines on the starship ) 6opl;pf8bqi NO-PAIN-NO-GAIN are suddenly turned off, while traveling in empty space, the staq of6;blp)ip8rship will

  A rocket moves through empty space in a straight line with constantkw5.xbc.zt5v speed. It is far from the gravitational effect of any star or planet. Under these conditions, the force that must be applied to ttzx w..kcbv 55he rocket in order to sustain its motion is

  You are standing in a moving bus, facing forward, and you suddenly fad6z acrkj a+p,o(u f+1ll forward. You can imply from this thatjok(+ +aau 1fp,dcr6z the bus's

  You are standing in a moving bus, facing forward, and you suddenly fallvv x:envq30 o; forward as the bus comes to an immediate stop. What force caus:x3o0qnvv v; eed you to fall forward?

  A constant net force acts on an object. Delz5i8ycy , ;ovscribe the motion of the object.

  The acceleration of an object is inversely proportional tfqst kt/dv 98g:l c(-yz 12 +ixhzcnk4o

  A net force F accelerates a mass m with an acceleration a. If 5 w 7 wpl7ff/kzy 3e4zsru9w0vthe same net forczwpewlyz7 0f kv35 rw/4u7 f9se is applied to mass 2m, then the acceleration will be

  A net force F acts on a -l r5xz *xc.n24nkfod mass m and produces an acceleration a. What acceleration resul n4x 2o.-l5f dkczx*nrts if a net force 2F acts on mass 4m?

  If you blow up a balloon, and then release igbi0-hxrb x-d mu.8)qk-w p7 nt, the balloon will fly away. This is an wi -)-gx rm- .bq0d87kxhb npuillustration of

  Two cars collide head-on. At every m;yipb 43ehhm)txm r: 4u44kiyoment during the collision, the magnitude of the force the first car exerts on the second is exactly equal to the magnitude of the force th 4m: 4x4mkyy;i hb3 uhr)e4tipe second car exerts on the first. This is an example of

  If you exert a force F on an object, the force whicg3ny:o p)3fp)wxyze * +vz1lch the object exerts on you wi1wxy l :+p3z)fcey3no p)g*zvll

  Action-reaction force4b/ r,rpjx+e5: ljavr s

  Action-reaction forces aro*z;i;hn2tc xe

  A 20-ton truck collides with a 1500-lb car and causes a lot of da2y,-x v-43yqu*whwwluafbv rh l1;s.s8l 6mq mage to the car. Since a lot of damag,hwv-a-v4 w1h;uy 2s6*wulylls.bmq q8x3f r e is done on the car

  An object of mass m sits on a flat table. The Earth pulls on this object wit6ve ep. 8lylx(3n -gnt1bxzm 5h force mg, which we v 1 5mgbe penl8 3(xzntxl6y-.will call the action force. What is the reaction force?

  A child's toy is suspended from the ceiling by means of a string. Tscx-)szt d/m ulhnm5mv3f7(o uy/,y -he Earth pulls downward on the toy with its weight force of 8.0 N. If this is the "action fu /yhf -, )m/dvt om3l5xsuy-( csnzm7orce," what is the "reaction force"?

  Your bat hits the ball pitched to y3,2:jgh5ke n.oyg3gjiq j . saou with a 1500-N instantaneous force. The ball hits the bat i 3gk3 jn2ej ,y.oj5:hq.gsga with an instantaneous force, whose magnitude is

State Newton's three law6e1kylxmblw;+ ;jpk ;s.

  Mass and weight

  The acceleration due to gra +t9+ wkxa1jjxp:l*onvity 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, compkoa:1x pw x9j+lj*+ ntared to Earth?

  An example of a force which acts at an.vqc / gn6)gd distance is

  Who has a greater weight to mass ratio, a person weighing 5f.w yobhi0.-j3 vcwg0ebv+hs f+:hy400 N or a person weighing 600 Nwbbf+: sev3gf 0jcow .hhy0hvy.+ -5i ?

  A stone is thrown straight up. At the th,x1(yetq01 3jwrjshwooks z,2n i,s od:w 68op of its path, the net force acting on :kwss1s86,z1,yh h rw (ow3i0nq oj2dj,o et xit is

  A 20-N weight and a 5.0-N weight are droppe)-l43ymioanq w )k h4hd simultaneously from the same height. Ignore air resistance. Compare their accelerayo-h i44 )3anwl)qmk htions.

  A brick and a feather fall to the earthxwmh /:6c: 7(zi/kq krbgwrc- at their respective terminal velocities. Which object experiences th rw(-xqm/7:iz /h6kbrkw:c gce greater force of air friction?

  An object of mass m is hanging by a string from the ceiling of an elevator. s(mc*h fitxs /;o/o8t, aw2td The elevator is moving up at constant speed. What is the tension in theo, t/t scw/8( io 2dxast;*hfm string?

  An object of mass m is hanging by a string from thei+ozbaq 4xi48 ceiling of an elevator. The elevator i+o 4aiz84qbixs moving upward, but slowing down. What is the tension in the string?

  The force that keepscic;2ew: 9-ph svq++ :evc;nfq as.q q you from sliding on an icy sidewalk is

  It's more difficult to start moving a heavy carton from r/e8igf8,nc i yqcti*- est than it is to keep pushing it with con/8-g*q yiti c cne8f,istant velocity, because

  A horizontal force accelerates a box from u 1j4)5r -h4yeqolmpsvju,9q5upc ,srest across a horizontal surface (friction is present) at a constes5u,h lpq4p myo4cq1u-)jvsj 9,5 ruant 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 velocity. Thus w:a9vkai dc1/a e can deduce th 1/:c9vda iakaat

  A block of mass M slides down a frictionless plane incgyn ,on4qpcl, 9 ms,x7lined at an angle q with the horizontal. The normal ,o ,npgqy ,9m4xlc 7nsreaction force exerted by the plane on the block is

  A block of mass M slides down a frictionless plane inclined at amz326l ; ofy3amyf/jdn angle q with the horizontal. The normal reaction force exerted b d2f lfam/y3yo3z;6mj y the plane on the block is directed

  A block of mass M slides down a ku4du.n 6i(cd frictionless plane inclined at an angle q with the horizontal. The gravikdu4c( un id6.tational force is directed

  Two toy cars (16 kg and 2.0 kg) are rele xti8 m 4j:c8mj3nx9alased simultaneously on an inclined plane that makes an angle of 30e with the horizontal. Make a statement which 4j8a xmjx98 cm l3it:nbest describes their acceleration after being released.

  An object sits on a frictionless surface. A 16-N fo)9 kv1kwbe8n0i2ttxey cs7(grce is applied to the object, and ig2ewiykex kt)n9(8 v 1c0tb7st accelerates at $2.0 \; m/s^2$. What is the mass of the object?

  A sports car of mass 1000 mw yz)w859os.: dhxga kg can accelerate from rest to 27 m/s in 7.0 s. What is the aa:9zh5 w 8msy) .xgdowverage forward force on the car?

  Starting from rest, a 4.0-kg body reachexljl9rf c* z wf++j)q.s a speed of 8.0 m/s in 2.0 s. What is the net force 9+jxcjw rl +zfl*.fq)acting on the body?

  An antitank weapon fires a 3.00-kg7ou71c 1sig4vys(fno rocket which acquires a speed of 50.0 m/s after trcovossin4u1g 7yf(1 7 aveling
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 tl ez) n zbj/wj+:tx-p;hat you push a 10-kg mass from rest +znbj p)x-tl:/w z;ej,

  What is the mass of a person wh 5 h5rnzj5tby9l)l3opao a*j /o weighs 110 lb?

  What is the mass of an object that weighs 250 N liyw1 x9 y26.g m/bhiyu sgz0r6fg* 9eon the surface of the Earth where the acceleration due ib9ly6 fy*0wryshz1 g9mux .g 2e6gi/ to gravity is $9.80 \; m/s^2$?

  An object has a mass of 60 kg on the Earth. What is the mass ofn 76aj f l11)xx .dddnz+f,kbe the object on the surface of the Moon where the acceleration due to gravity is only ,d1e dnzd +nf17)xkx6b .lfaj1/6 of that on the Earth?

  Object A weighs 40 N on Earth, and object B weu*/avom2f nyk6 , yo9lmw dp,;ighs 40 N on the Moon. The Moon's gravity is one sixth of Earth's. Compare the masses of the objects * wa96p2kd,;n /o, foulvymym.

  Sue and Sean are having a tug-of-war by pullingmz**l+ d ysd6f 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 Sld6y* sf *zd+mue at $2.0 \; m/s^2$?

  A stack of books rests on a level frictionless surface. A bzl,bn 9hepd a 0i52w*force F acts on the stack, and it acchep lbb* 5d,nw9i20z aelerates 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 s9m6o 0 qxwy2eitands on a scale in an elevator. What will the scale be reading when the elevator is accelerating downwarx qwim209o y6ed at $4.00 \; m/s^2$?

  A person on a scale rides in axvi1x a )19xann elevator. If the mass of the person is 60.0 kg vaax)i11x9xnand the elevator accelerates downward with an acceleration of $4.90 \; m/s^2$, what is the reading on the scale?

  A person on a scale rideu5 isusteo pi; *d: )xk+bl16gs in an elevator. If the mass of the person is 60.0 kg and the elevator accelerates upward with an accelegbli5 ikp 6 t ou*u+s;)1sxde:ration of $4.90 \; m/s^2$, what is the reading on the scale?

  Two horizontal forces+ jd0e.yv *and act on a 5.0-kg mass. One force has a magnitude of 8.0 N and *yn 0dde+vja. is directed due north. 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 flatbed of a tru:vvgzml e; si5sj(.8eck. It is held in place by metal brackets that can exert a maximum horizontal force of 9000 N. When the truv5. j 8mvs:ez;lis e(gck 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 rest3uck,os 0 gltqe 1k*-9sozl d(s on the flatbed of a truck. It is held in place by metal brackets that can exert a maximum horizk tg(oe*9 lq z luc1,d3ksso-0ontal 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 into the cab?

  In the Atwood machine shown in Fig. 4-1, if M = 0.60 kg and m = 0.40 kg, whav*s8bn5o+.ef scp qs5t is the magnitude of the acceleration of the system? (Ignore friction and the mass of +sb*8v.ne5sqf p oc5sthe pulley.)

  In the Atwood machinannw 7idc05wf 66 gs umf3q5qddq.h12e shown in Fig. 4-1, if M = 0.60 kg and m = 0.40 kg, what is the tension in the 6s nqn dc 5 i3gaq1w7.dd0uq6whf2m f5string? (Ignore friction and the mass of the pulley.)

  A student pulls a box of books on a smooth horizontal floor wit2jh nu. wht az.4-gzu6h a force of 100 N in6zjwu4g nz..t -uahh2 a direction 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 boxlb n3jk/;s o9ajm)e7q of books on a smooth horizontal floor with a force of 100 N in a asmj l9nqo;e 3 b7/k)jdirection of 37.0e 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 supportc 03uxe;qld 0( 6c1ns)d qumvged by two ropes as shown in Fig. 4-2. What are the tensions in thd u0;e)c6c3mqv nd0(uql xsg1e ropes?

  In Fig. 4-2, if the tensions in the ropes are 50 N, what is the mass of the traf5r 3.5 0hnr 9ciobmx sk(;ynlxfic lxhl0 ci95k xmn( b;ros53.y nright?

  Two boxes of masses m and 2m are in contact with eawtv6e2a2 8 5*ax k;xmq7mzw rzch other on a frictionless surface. (See Fig. 4-3.) xw;r8z 2kt7m* 6a5aqmxwezv2What is the acceleration of the more massive box?

  Two boxes of masses m and 2m are in contact with each other on a fricqbm ;fe. ev-xn3xw. p(tionless surface. (Sm - (e;f3 vqnewbx.xp.ee Fig. 4-3.) What is the net force on the more massive box?

  Two boxes of masses m and 2m are connected by a rope. (See Fig. 4-4.) If the f mg .6kwhbzun;e/ph pmlgmd /n54, .y7orwarddkn,hw; nm..eml h bgp46 7z5/p/yg mu force on the more massive box is F, what is the tension in the connecting rope?

  Two boxes of masses m and 2m are connected by a rope. (44p5xsfp xv8yb 6z rk;See Fig. 4-4.) If the forward force on the more massive box is F, what is the acceleration ofv4pk 6z5x;xp8b4syrf the less massive box?

Two boxes are connected by a cord running over a pulley as smizj3*- ld- ulqbeb. 0hown in Fig. 4-5. Box I uj *i-m qlz-elb0.db3 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 kineti;qt .,ac hfezg(-b0 uhc 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 force0e;(zf.,ag t hh-cqb u is applied to the box?

  The coefficients of static and kinetic fric*wrk;kwvf-o-e-gp 8ed7c r+ctions for plastic on wood are 0.50 and 0.40,k+7p fwgro-;ce*v-w edk cr8 -
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 surfa+p 2 h:ahqw6usce in the +x direction. It slows and comes to a stop with a constanw6hah2q+:u ps t 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- 1c-m0 o.*pqr7szb+ss; r)m( tkmw bubN force. A 3.0-N friction force retards the motiowosbmp1*trb;s . qb(ck r0 ums-zm +7)n. What is the acceleration of the object?

  A horizontal force of 5.0 N accelerates a 4.0-ee1o j lzubz2/ge/23hxfy:0c 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 z. *:wm olrzbd36p6oo :xw-w vs89axegiven an initial speed of 10 m/s. It slides 50 m on the ice before it stops. Wha.rse:w pwz9l *od :63box8z -6xwvamot is the coefficient of kinetic friction between the puck and the ice?

  During the investigation of a traffic accident, police find skid marks 90.0 opsty )a6qkh1- rahz 0f,u r8h6-ra:am long. They determioq06zrh uar:fha-6,s a 81ytkrha-p )ne 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 when the brakes were applied.

  Two boxes of masses m and 3m are stacked. (See Fig. 4-6.) 9t4y 8zc0*jlrc f /l* tu6plhqThe surface between the more massive box and the horizontal surface is smooth and the surface between the boxes is rough. If f j*8t9hlr/c 6pzy0 l*qtuc4 lthe 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. (See Fig. 4-6.) hqkq jb5gf-mq9-q( d0 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 massih9qbf k-0m 5d (gqqqj-ve box, what is the coefficient of static friction between the boxes?

  An object is on a fricyy n,03yw dh8ationless inclined plane. The plane is inclined at an angle of,0d 3ay8hny yw $30^{\circ}$ with the horizontal. What is the object's acceleration?

  A 10-kg mass slides dow1cujzut7 g j(o+ p+;y1f,lhxn n 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 smooth9 h y6f e+i6fqij-qg3z 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 po* m6 qb)kw2m3 e8i u7qk+jn-kfo9hd 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, at a )g0 gbv. qjq2xconstant velocity of 6.0 m/s.g.)g0q j2 bvxq
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 rouguja) mdj.fd1c9*tu)n2 sbc*nqkdd9 4h $37^{\circ}$ inclined plane where the coefficient of kinetic friction is 0.20. What is the acceleration of the object?

  An object with a mass j c-bfgd/2 * jdybnc8n(i4m7y 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 rough surface. w*gvmw7cu4 m48u9ucb4 poa p0The cable attached to the log m84c0cu u4muo 9p bwawm*gv47pakes 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 fr:es:2nvnq789 cthwrn om rest on a rough inclined plane tilted at an angle ofqehr:tnnsv8 2c9 n:w7 $33.5^{\circ}$ 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 a lu(q 3qpzku g;4)30uczkl9wtn inclined plane. The angle of incline is gradually increased until the object begins to slide. The angle at which this occurs i 3k0w3qcu;z tkuzll)pqu(g94s q. What is the coefficient of static friction between the object and the plane?