Which of Newton's laws best explains why motorists should buckle-up?/w.y+c2n-gtk, kfwbg

  When you sit on a chair, the resultant force on you iscjd l4u yys0v05i*4 oj,b( /a+hrrfqi

  In the absence of an external fo3p k96o.fce (dxpv1 6kqmw0 ftb kr71xrce, a moving object will

  When the rocket engines on the starship NO-PAIN-NO-GAIN areuv-kee 0 gtz 8xlz9;p8 suddenly turned off, while traveling in empty space, theguvptek9 -x ;0ez 8l8z starship will

  A rocket moves throughz-i5rp*0q/6:rb o ul:uvx w; 6cpiqly au9qg0 empty space in a straight line with constant speed. It is far from the gravitational effect of any star rpyilrqx6guao;zv* c6l- u /b0wp q u95 ::0iqor 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, facing forward, and you sudden(5rm 5h*ozmp8qjwq d8 ly fall forward. Y mq8w85 hjmzd*qo5(rpou can imply from this that the bus's

  You are standing in a moving bus, facing forward, and you suddenls4v ,/ nul;4 bxv7ubyzy fall forward as the bus comes to an immediate stop. What force n/4l zxbv ;sy4u7ub v,caused you to fall forward?

  A constant net force acts sm5 t9y(pb m9 ct;qn*xon an object. Describe the motion of the object.

  The acceleration of an object isvmauwg 8u(+8a inversely proportional to

  A net force F accelerates a mass m withpvxmz 7o ab3a jxx4-,, an acceleration a. If the same net force,4 mx 7pvx x,o3-zbjaa is applied to mass 2m, then the acceleration will be

  A net force F acts on a mass /elvn7elt-+.wz4b jw 1hgmmy7 6m(mtm and produces an acceleration a. What acceleration results if a net force 2F acts on mass 7 wgm7tzj+l4mtbv-(e /nml6 wh1 .eym4m?

  If you blow up a balloon, and then release it, the balloon zncv *1uuy4lu y-- )miwill fly away. This zv-unu 1l*)4ymyci- u is an illustration of

  Two cars collide head-on. At every mop7 bsx3x9 idqp./-s3jbp.1 zwo cwhx)ment 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. dpbpx -33xw7bj9w1qc p)zss. xoi./h This is an example of

  If you exert a force F on an object, the force (jvfzc 7) v+qluh2vdp 28kyf+r/ ,bx ohl1me0which the object exerts on you willl fy2xjq md h2z o1ehb8,c7f+)v0vp(/ur+ lvk

  Action-reaction force) o a gvk:zs ,l4p5lws37wmu:ws

  Action-reaction forceqc :kebj.sjp6u;s6 4rs are

  A 20-ton truck collides with a 1500-lb car and causes a lot of damab 0rvky,d x.7s9pgp(03uk kv jge to the car. Since a lot of dampkks xu0y370, bjp.k(vvr9dg age is done on the car

  An object of mass m sits on a flat table. The Earth pulls on vyj-o 65ylf; f/n1a9qzl rj 0ythis object with force mg, which we will call the action force. What ifo15/;y l9 f6yayrl- jnqzjv 0s the reaction force?

  A child's toy is suspended from the ceiling by means of a stringr v b.j/wdhb+w /2dj8e. The Earth pulls downward on the toy with its weight force of 8.0 N. If this is the "actior vb/ j+ewdw8.bd /j2hn force," what is the "reaction force"?

  Your bat hits the ball pitched to you with a 1500-N instantaneous force.zj g 2p21jw -ol 3noyhx4nzg5ea8sjc6 37z 3ag The ball hits the bat with an instantaneols73ho8 g5oc313jnj j e2a n y4wa2zpg -6zzxgus force, whose magnitude is

State Newton's three d p(lm*+;x yxeupw l./laws.

  Mass and weight

  The acceleration due to gra2(i 0rn hbvqkja1o .(lvity is lower on the Moon than on Earth. Which of the following is true about the mass and weight of an astronaut ok(v1nj. 0 brlqoa(2ihn the Moon's surface, compared to Earth?

  An example of a force which acts at a dis4ekd m.dmcc y3e4im8 +tance is

  Who has a greater weight to mass ratio, a person weighing 400 70mgbn ,yxt oylt g3etf..iquo-f4*z9g 0t 0nN or a person weighing 6000ie bf- totgg y407otuxf.qm z0yt n3, ln.g9* N?

  A stone is thrown straight up. At the top of its path, thez*jqbs op *g7d-pvbp1-/gi (k net force acting on it pdg /qpsgvk z1(j* -bi-*7pbois

  A 20-N weight and a 5.0-N weight are dropped simultaneo93prd-vb0: dk dv7fp,l vs4xausly from the same height. Ignore air resistanr3pv sa,v kfpx04db-9lv7d d:ce. Compare their accelerations.

  A brick and a feather fall to the earthj;3rw dp,2xne at their respective terminal velocities. Which object experiences the greater force of air fricte;w3rxn2j ,dpion?

  An object of mass m is hanging by a string from the ceiling of an el a/7 p9w*tlxr.z hwp,pevator. The elevator is mova7,x. lr tw/ hp*pp9zwing up at constant speed. What is the tension in the string?

  An object of mass m is*v(wq;y-x *us t1 c;nl 0jqdom hanging by a string from the ceiling of an elevator. The elevator is moving upward, but slowing down. What is the tension inq* c q(sxvw1jtu;n yd-m0* ol; the string?

  The force that keeps you from sgxi28c wl.iz u-enr 2tm3zl +.liding on an icy sidewalk is

  It's more difficult to start moving 5+;mraxc3 irh gtbbj /x* beq. uo*:(ea heavy carton from rest than it is to keep pushinm5e *tqa+ cb3;bxrjguo.i r(ebhx : */g it with constant velocity, because

  A horizontal force accelerates a box from rest across a xiouiz/ 2k*e;a4 4koq 07vcoa horizontal surface (friction is present) at a constant rate. The experiment is repeated, and all conditions remain the same with the ex7 eo4i0vi4 ou*aok ackz qx/;2ception that the horizontal force is doubled. What happens to the box's acceleration?

  A packing crate slides down an inclin r q k5rq5hm+.swc5/mped ramp at constant velocity. Thus we can deduc r.rh+k5qmwqp /mc5s5e that

  A block of mass M slides down a frictionless plazhsw m) p7jhro l);-x+ne inclined at an angle q with the horizontal. The normal reaction forc -)h ;+)wp xljrzmsoh7e exerted by the plane on the block is

  A block of mass M slides down a frictionless plane inclined at an angvvowo1.m /h 9irc( )lule q with the horizontal. The normal reaction forco) 1/. lowrhmiv vu9(ce exerted by the plane on the block is directed

  A block of mass M slides down ) +p 5kslg9gpwrxhi32a frictionless plane inclined at an angle q with the horizontal. The gravitational force is directs2pi5w g)hk3+lp rx9ged

  Two toy cars (16 kg and 2.0 kg) a p5j3rsq kzkp92i)9xjre released simultaneously on an inclined plane that makes an angle of 30e with the horizontal9zix 2jrkjk5p 9)qp s3. Make a statement which best describes their acceleration after being released.

  An object sits on a frictionless surface. A 16-N force is applufc 38.re *0xxg ,dxl rqt*)asied to the object, and it acceleraf83gr *aexxsr0)l*c .xu td, qtes at $2.0 \; m/s^2$. What is the mass of the object?

  A sports car of mass 1000 kg can accelerate fro2c;; n2cvqc nl*s/aytm rest to 27 m/s in 7.0 s. What is th;*; s 2 qc2vnnalc/ctye average forward force on the car?

  Starting from rest, a 4.0-kg body reaches a speed of 8.0 m/s in 2.0 s. What ij*8 2jr0iqa o swei7j(s the net force acting on r*(8jsaoj 0 jq72iie wthe body?

  An antitank weapon fires a 3.00-kg rocket whicv5v(wdr 5*rlxf2. bqvh acquires a speed of 50.0 m/s after trav x5fl( wd5 qr2vb.rv*veling
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 4pwq8tz*bv0 0rgj c j+mass from rest,0 *t8q+ bvwjpjrgz40 c

  What is the mass of a person who weighs 110 lp 7 u b*ruciscv)1j 8k8+b7xanb?

  What is the mass of an objecti23 k5w:zb j,2xihpnh that weighs 250 N on the surface of the Earth where the acceleration duii3 22,5pxwh nb: hzjke to gravity is $9.80 \; m/s^2$?

  An object has a mass of 60 kg on the Earth. What is the mass of the object on t1) )y-+dj izv cwku*cihe surface of the Moon where the accelei+) z1-*kj)wcdiyvuc ration due to gravity is only 1/6 of that on the Earth?

  Object A weighs 40 N on Earthbz*:o i8edfbe36m .yg , and object B weighs 40 N on the Moon. The Moon's gravity is one sixth of Earth's. Compare the masses of the omge*83 ebdzy6b fi. o:bjects.

  Sue and Sean are having atzneg4 4, i3qx tug-of-war by pulling on opposite ends of a 5.0-kg rope. Sue pulls with a 15-N forcegzqxi4 n43e, t. What is Sean's force if the rope accelerates toward Sue at $2.0 \; m/s^2$?

  A stack of books rests ng2amjob1m d.hd81xd)rj-6y v vu,*b on a level frictionless surface. A force F acts on the stack, and it accelerates a 26bn*1j1uvm,oyvdg) .jhbm8a x dr d-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 on a scale in an elevator. What wm3yqd/y d. gy/(iyf/p ill the scale be reading when the elevator is acceldd/yg.3ypyim/qy (f/erating downward at $4.00 \; m/s^2$?

  A person on a scale rides in an e3 c fvuff 1dtgvi0m0k4w*(m1 tbr/z1x levator. If the mass of the person is 60.0 kg and tmd(xzr1fiv b 1 /u4 0 vtf*mgwk13c0tfhe 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 the mass of the person is 60.r8a maa:zg*u: 0 kg and the elevator accelerates upwa8muz aag: :*rard 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.vui: vq7r9oa 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 acce9:u qovrva.7 ileration of the mass?

  An object of mass 6000 kg resljbj-9kipp;;q 7t:pkx5 5eu s3t py b8ts on the flatbed of a truck. It is held in place by metal b 3up9pxjtyi q;8jkl5bep- 7bs: 5t;pkrackets 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 6000 kg rests on the fltw m2j b8snn+,f:vp 6fatbed of a truck. It is held in place by metal brackets that can exert a maximum horizontal forcef j6bmn2p,vsf n8+:wt 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 sai+i8g.qwo3xww9byr +;aj 7o 9r2 xexhown in Fig. 4-1, if M = 0.60 kg and m = 0.40 kg, what is the magnitude of the acceleration of the 29 agr q;ow 3.xj+iwo+ eaxy7xi9b8rw system? (Ignore friction and the mass of the pulley.)

  In the Atwood machine shown in4iy .;7m6j+ru7 wwuqjltjo6d Fig. 4-1, if M = 0.60 kg and m = 0.40 kg, what is the tension in the string? (Ignore friction a.d7r m joy7+4wu6jjwq; iult6nd the mass of the pulley.)

  A student pulls a box of books on a smooth horizontal floo u4n5;0yyek s7 dfnvq,r with a force of 100 N0nn,4 qfdu7e yy5 ;svk in 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 box of books o*ru 5dw+vt tl.n a smooth horizontal floor with a force of 100 N in a direction of 37.0e above the horizontal. If the mass of the box.w+t ud5ltr *v and the books is 40.0 kg, what is the normal force on the box?

  A traffic light of weight 100 N is supported byzb4gi/f4ru,y two ropes as shown in Fig. 4-2. Whufgyr4zb4 /i, at are the tensions in the ropes?

  In Fig. 4-2, if the tensions in the ropes are 50 N, what is the mass w+ij *fbm8rjlixd (4 :mxhl, *i6k/oaof the traffic ligjw*(r+m 86hxa x /o:l ,kl4mdiibifj *ht?

  Two boxes of masses m and 2m are in contact with each other ot pudp;o wnu:9j+-e m-n a frictionless surface. (See Fig. 4-3.) What is the acwneud-tpm 9j+ o;-p u:celeration of the more massive box?

  Two boxes of masses m and 2m are in bntlta /rw, ya+; x/0 tzngys //f: 9t-ya+fcncontact with each other on a frictionless surface. (See Fig. 4-3.) What is the net force on the more massiv + cyn :tn zfg/ na ay/ly+ab,f/t-/9xwsr;tt0e box?

  Two boxes of masses m and 2m are coos3 g og0kic.*nnected by a rope. (See Fig. 4-4.) If the forward force on the more massive box is F, wo kiogcsg 30*.hat is the tension in the connecting rope?

  Two boxes of masses m and 2m aqpiayc;.*oi3-j g;in re connected by a rope. (See Fig. 4-4.) If the forward force on the more massive box is F, wh a cy;iq3jp io;ig*.n-at is the acceleration of the less massive box?

Two boxes are connected by a cord ru6)5qc+xjj 5ls93a pm pi p-qmlnning over a pulley as shown in Fig. 4-5. Box I -5 +lipqm 59)msjp3qlc j a6xpof 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 frictio m9n7xy*7rlrg ns 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 forcelr79g7 yrmx*n is applied to the box?

  The coefficients of static and kinetic frictions for plastic on wood are r/ nd x0p70ajkv i-qxu,kf2 7fpe,7cn0.50 and a7 xj0 fk2,7,i-v7nq xe 0ducknpr /pf0.40,
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 d hn nq6m3;jrn0irection. It slows and comes to a stohn3 q0;nm6rnj p with 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 horizontal surface is pulled by a 5.0-N force. A 3134kp qtj o9pxho :u;v.0-N friction force retards the motion. What is the acc;phjp:93 ook4qtxuv1eleration of the object?

  A horizontal force of 5.0 N accelerates a 4.0-kg masscr0cn2 7l jsm1, 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 slides zv*6ist auy m5 094 .bnnke(hl50 m on the ice before it stops. What is the coefficient of kinetic friction between the puck la0( bnky* zsv6et9h 5n4u.i mand the ice?

  During the investigaf9lm9we0d0.zod u 3qy tion of a traffic accident, police find skid marks 90.0 m long. They determine the coefficient of friction between the car's tires and t .0mz9foly0ewdqd 9u3 he 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 F y5,k8xp.6 o j55iwzjrju4 nfaig. 4-6.) The surface between the more massive box and the horizontal surface is smooth and the surface between the boxes is rough. oy fjj8az rj5i5kpxw5u 4,6. nIf 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 stackebflab05 /v0p11jmwk cga, s5r d. (See Fig. 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 less massive box does not slide on the more massive box, what if1 r1gcws0 05,kv5al/ pbbajm s the coefficient of static friction between the boxes?

  An object is on a frictionless inclined plane. The plane is incline qz4+f2oaeels2f1sszy7nu93d at an angle lnu7s 4sefyq oz2ez2f1as93+of $30^{\circ}$ with the horizontal. What is the object's acceleration?

  A 10-kg mass slides down awftqxg/3q8/yw* f/eg1pa ) zz 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 inclined plane with an angle qs6i8yth 3f/u 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 an angle ip gx7hr 70: g5d6ehtm-tomw1 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 direrlt 1xaq2:i)zb ghh)/ctly down an inclined plane, at a constant velocity of 6.0azgh rx b/:q2)1tl) ih 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 rougzdfq 99o4g6c tcmw;c :h $37^{\circ}$ 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 down vc ckux0)o:/ma 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 r 1.s)p,slmu tswgo2;r.k-sg;pq6n f weighing 500 N along a rough surface. The cable attached to the lo- tul, ..qw)s;gro gr kp6 2f1s;smnspg 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 rest onzl y)jkk3 w c e31b*sa 6-r,.yuj*pctp a rough inclined plane tilted at an angle o.e13-rbykpca kjl)u j36wy* c,psz*tf $33.5^{\circ}$ 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 planeaoe8zrtm4; b a* :jt :)m2nhqf. The angle of incline is gradually increased until the object begins to slide. The angle at w8q) 4a;::hm2b ntjrot aef*mzhich this occurs is q. What is the coefficient of static friction between the object and the plane?