Which of Newton's laws best explains why motori j*i,82*hluw q legxmn +,ngl-sts should buckle-up?

  When you sit on a chair, the resultant fou(5,rrfvoekak80f95k3g c lk rce on you is

  In the absence of an external force, a moving objed,wll7mr)ckj5v (k xe.r/6zlct will

  When the rocket engines on the starship NO-PAIN-NO-GAIN are suddenly tuxpjkwac 78-2sht 2k3vrned off, while pkh 2ac78kxswv -2jt3 traveling in empty space, the starship will

  A rocket moves through empty space in a straid jw +d28zi:xx6fzyc d.mf:b3t0bj i8ght line with constant speed. It is far from the gravitational effec6.xbcdmib08w jzd j::ty2if8d+ 3 xf zt 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, facing forward, and you suddenly fal49ps5va3uan+l0yh qx l forward. You can ip4v+layua0 5x3nhq s9mply from this that the bus's

  You are standing in a moving bus, facin nw.0peu; z;v7vqcye.g forward, and you suddenly fall forward as the bus comes to an immediate0ve ;. .n;wq z7cyuvpe stop. What force caused you to fall forward?

  A constant net force0zzy 2d. cnqicz5w*i/tkc3 .t acts on an object. Describe the motion of the object.

  The acceleration of an object is inversely propor.x8d4 aw v;aoc 42jvgmtional to

  A net force F accelerates a mass m with an accelerationsox,h vjs1+ (n a. If the same net force is applied to n(1vssj +hx,omass 2m, then the acceleration will be

  A net force F acts on a mass m and produces an accelerationc cpm)7j ygh10 a. What acceleration results if a net force 2F acts on 1 y7)c0cpgmh jmass 4m?

  If you blow up a balloon, anyu)da s5jifd( e7n ids04yb,7 d then release it, the balloon will fly away. This is an illustration ofyne s0a5s y77j4 i d)dfuib,(d

  Two cars collide head-on. At every moment during the colli(3wsi0 j yix/j ud.u-h;3g inision, 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 an example .ij;-xigh(/ujd u3 3yn0 iw isof

  If you exert a force ci134bb6x- l fpi 5hp-4vmjsh F on an object, the force which the object exerts on you wil 1 hmvsfliib5c 34jpx64p--b hl

  Action-reaction forcj9wsoc cqomk (6 sqw+)btswv +/)tf*0es

  Action-reaction forcesdw0.pw vq4h4n-nkbd h39 rp4f are

  A 20-ton truck collides with a 1500-lb car and causes a dvtingq(3lg htw7c2 j4chc;w -s+9 0hlot of damage to the car. Since a lo ( sh49; +0clgvwc7 -wtgh2id3jhnqctt of damage is done on the car

  An object of mass m sits on a flat ta*tg qq+dfu)6t g6z*9/8wzhmlrpu jc0ble. The Earth pulls on this object with force mg, which we will chc6lf w+tu9z qur/)*m gq 8jd6*pzgt 0all the action force. What is the reaction force?

  A child's toy is suspended from the ceiling by means of a string. Theyq-8 cuwe1pv8 Earth pulls downward on the toy with its weight force of 8.0 N. If this is the "actio vec- yp818uwqn force," what is the "reaction force"?

  Your bat hits the ball pitchedra+i8 s/ jb8td to you with a 1500-N instantaneous force. The ball hits the bat with an instantaneourj8aib8s / dt+s force, whose magnitude is

State Newton's three laws.h2b*w wby yju *5eh0i(

  Mass and weight

  The acceleration due to gravity is lower on the Moon thann2yj(8;w lhcb on Earth. Which of thhb2jw ln8y (c;e following 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 di.*:o 3u0gaht 6mkzpscstance is

  Who has a greater weight to mass ratio,gr 7v ip98n-iscds79sk9 f7 ge a person weighing 400 N or a person weighn7 9 i97csds gps7i8gfv-ker 9ing 600 N?

  A stone is thrown straight up. At the top of j.,m yq/iwtl3 its path, the net force acting on itm 3/qwj.ti,l y is

  A 20-N weight and a 5.0-N weight are dropped simultanj r+a+r2md)tseously from the same height. Ignore air resistance. Cor+ d +r2jsat)mmpare their accelerations.

  A brick and a feather fall to the earth at their respective terminal velocities.i b1)dt4 1 pab-.4pzcm zgs*su Which object exdiau*z4b4 ptcs-z. 1 s) mp1gbperiences the greater force of air friction?

  An object of mass m is hanging byrdiiw2vl5hoi44z 9 5v a string from the ceiling of an elevator. The elevator is moving up at constant speed. What is the tension in theh idw iv52vlor9zi45 4 string?

  An object of mass m is hanging by a string from the ceil t6hc+uk.g qouhyw;4(8 n5v-zrr1cxe m-4kj qing of an elevator. The elevator is moving ut vuqk5h-y c(8 -e+4 og.chrwkx4r u16q ;znjmpward, but slowing down. What is the tension in the string?

  The force that keeps you from sliding on an i+ ) ))tlqjro;h k+vlz g6k3 q*vwmxyz qr)t,+mcy sidewalk is

  It's more difficult 8uoucwu9i h 66to start moving a heavy carton from rest than it is to keep pushing it with constant velocity, becoui uu6w96 c8hause

  A horizontal force accelerates a box from rest across a horizontal sz 88 pclgbaur( 6)0umaurface (friction is present) at a constant rate. The experiment is repeated, and all conditions remain the same with the exception t8auacz 8(r b6ug0p lm)hat the horizontal force is doubled. What happens to the box's acceleration?

  A packing crate slides down an incl*rtdul 5xco .ho1/;klined ramp at constant velocity. Thus we can deduce;l/o.uo *dlc5txk hr1 that

  A block of mass M slides down a frictionless np0zvdqju208cq rzg4 lr)v.9plane inclined at an angle q with the horizontal. The normal reaction force exervzq90 2 rl)4z pug dcjqnr0v8.ted by the plane on the block is

  A block of mass M slides down a frictionless plane inclined at an angle q witkyzxi 0-68g7vmx;ftqh the horizontal. The normal reaction force exerted bx68;f07 tv -izgyqx kmy the plane on the block is directed

  A block of mass M slides down a frictionless plane inclined at an(c6-z oge lg7m angle q with the horizontal. The gravitational force is die ggz67(olcm-rected

  Two toy cars (16 kg and ,d:mig; gfvj6wlg4a ;2.0 kg) are released simultaneously on an inclined plane that makes an angle of 30e with the horizontal. Make a statement which 6:vg ;l;m,wa g4jgfidbest describes their acceleration after being released.

  An object sits on a frictionless surface. A 16-N force is applied to the obzpeilx28 ,/ zxject, and it accelerates a2,pl/ zxe xi8zt $2.0 \; m/s^2$. 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 sstx3mz0o yr// 1p bl2o. What is the 0m2y /o1b3xrst/zolp average forward force on the car?

  Starting from rest, a 4.0-kg body reacho1t(3 dcdg fen ,yauwe1-a9h+es a speed of 8.0 m/s in 2.0 s. What is the net force h c1-,eu o 1gt3daa(9+yfwe ndacting on the body?

  An antitank weapon fires a 3.00- x lptev52-c;skg rocket which acquires a speed of 50.0 m/s after lxe v2cs-5p ;ttraveling
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 ma lvv *ch- tb26;f;lgcm nd3k*gss with the same force that you push a 10-kg mass from rest*n fhcdc-; ;km*g6 lg2bvlt3 v,

  What is the mass of a person who weighs 110lz /+1qy t k,k7 hcax;low.4oo lb?

  What is the mass of an objecah(5 1xisk/f 4avlfi-t that weighs 250 N on the surface of the Earth where the accelkl x/ a514-ivffas( hieration due to gravity is $9.80 \; m/s^2$?

  An object has a mass of 60 kg on the Earth. mk (gk-xgmp++What is the mass of the object on the surface of the Moon where the acceleration du+ -+m px(kkmgge to gravity is only 1/6 of that on the Earth?

  Object A weighs 40 N on Eartn -iv(;vga9i9 ltvh f2h, and object B weighs 40 N on the Moon. The Moon's gravity is one sixth of Earth'vi (itfv 9 9-h2ga;lnvs. Compare the masses of the objects.

  Sue and Sean are having a tug-of-war by pulling s zz3vkj8ieny07 ap bc;9w.v3jwyd09on opposite ends of a 5.0-kg rope. Sue pulls with a 15-N force. What is Se;y v0e9 i3y9p7wja ksd3wz0ncbj .vz 8an's 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 x6 mj;u qigt;),9t wdhacts on the stack, j hxt)g9t;6dmwui,q; 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 inr rzl hp:5d4fryp)7p 3 an elevator. What will the scale be reading when the elevator is accele f73:lzh pryrr4ppd 5)rating downward at $4.00 \; m/s^2$?

  A person on a scale rid v)waw)1a 3wvdes in an elevator. If the mass of the person is 60.0 kg and the elevator accelerates downward www3aw))v ad 1vith 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 mas;0n5xajvkw hoqflu oh3hzqr;+ f,sis4 l16 :0s of the person is 60.0 kg and the elevator 0l q4o ok rx6hi;;whu +ss5 az:qf3 1,jnlv0hfaccelerates 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 magnitunbtihr r3 9u:0de 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 :b3itr09 nrhuacceleration of the mass?

  An object of mass 6000 kg rests on the flatbed of a truc3 v . igg7/j4:swgz inf+r;vf wu94oht8p dt(tk. 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 distance if the load is not to slij9v3ozf;f rwn gghs+wiit.p d(t:t4/ 48u7gvde forward into the cab?

  An object of mass 6000 k+ 5b/ mdfae dv6o et3h2-3dvulg rests 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 tob+dddfeaht-3 lo/vum 653 2ve slide forward into the cab?

  In the Atwood machine shown in Fig. 4-1, if M = h(x+os2rb f 8d0.60 kg and m = 0.40 kg, what is the magnitude of the acceleration of the (o8b fh2sd+r xsystem? (Ignore friction and the mass of the pulley.)

  In the Atwood machine shown in Fig+og yt;qsdl qun(4:m 8hyv8* 8*mtabv. 4-1, if M = 0.60 kg and m = 0.40 kg, what is the tension in the string? (Ignore yb t8:(; s gy *mnl8v* d4v8atu+hqoqmfriction and the mass of the pulley.)

  A student pulls a box of books on a smooth horizontal floor wicxc.qjbwtb0 , )ey val g*81.ath a force of 100 N in a direy8ve)a lc, ..wacbx 1* 0jtqbgction 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 z66k:0he hsfhc be 57c )qqf2dfw9j.b of books on 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 and the books is 40.0 kg dz6b6 bse)h0wjfqehcf97q cf.5 :kh2, what is the normal force on the box?

  A traffic light of weight 1003js; fm2pr lx6 N is supported by two ropes as shown in Fig. 4-2. What are the t6j;sm x3r2lpf ensions in the ropes?

  In Fig. 4-2, if the tensions in the ropes are 50 N, whah463zkc rdq:. 1v mohjt is the mass of the traffic lic:j1 4hk6.3zdmoqh rvght?

  Two boxes of masses m and 2m are in contact with each other on a frictionles,g454uki 78goewvm+. 0hk khb.4 p;dl ianzbas surface. (See 4. g pl0uzovh a5bheawd4;i4m+ ginb kk,.7k8 Fig. 4-3.) What is the acceleration of the more massive box?

  Two boxes of masses m and 2m are in3: .ysjvr-h uw contact with each other on a frictionless surface. (See Fig. 4-3.) What is the net force on the more massive3 h wvsy.j:ur- box?

  Two boxes of masses m and 2m ar2t+h v pseba,d 1/5otue connected by a rope. (See Fig. 4-4.) If the forward force on the more massive box is F, w5ots+ bvp 2a t,1ehd/uhat is the tension in the connecting rope?

  Two boxes of masses m and 2m are connected by a rope. (See F vu.)wgn,tsf ukm3 66/q)tovdig. 4-4.) If the forward force on the mnu /)qumw dts v. t)3f6v6kog,ore 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 k6z tyokc s4o*.3czx/ shown in Fig. 4-5. Box I of ma c/6cooyt3.ks4 zkx z*ss
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 and a4 o3rc14)5ltcsfr tbe/ou jq2 desk are 0.40 and 0.30, respectively. What is the net ttfq4s52r c) o/4 lc3br ouje1force on the box when a 15 N horizontal force is applied to the box?

  The coefficients of static and kinetic frictions for plas7 sl /cp1werr8tic on wood are 0.50 andp1s/rlwec8 7r 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 h;nmx*m ):s6rfzq*h o/:d4stm x/4 j: kquhrodirection. It slows and comes to a stop with a consta xrzsms m*tdukhx:44of*q)rhhq:/:j6 mno ;/ nt 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 fv n/pj z hu6f5dwh/8:on a horizontal surface is pulled by a 5.0-N force. A 3.0-N f8/df fh:h6p/n w5zujvriction force retards the motion. What is the acceleration of the object?

  A horizontal force of 5.0 N accelerates a 4.0-kg mass, from rest, at a rateczhrae 1l 6j0c/2hk3 b of $0.50 \; m/s^2$ in the positive direction. What friction force acts on the mass?

  During a hockey game, gyvm;r(s,/ ;uijox lrm.y/ (oa puck is given an initial speed of 10 m/s. It slides 50 m on the ice before it stops. What is the coefficient of kinetic friction between the puck x;.;(yovumm lo/ /,ir jyrs( gand the ice?

  During the investigation of a traffic accident, police f c/ s7vpwu23asj)aug*ind skid marks 90.0 m long. They determine the coefficient of friction between au3paus s 7c*v g2j)w/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.) The surface bewz8paz65baq:0 o drgk// c, jetween the more massive box and the horizontal surface is smooth and the surface between the boxes is rough. If the less massivekjq5wcgz/ze8r06 , p/:aobd a 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 ske.(cxro7z 9r tacked. (See Fig. 4-6.) The surface between the (ox r ezk7.r9cmore 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 static friction between the boxes?

  An object is on a frictionless inclined plane. The plany lvp tn(qgn j*3u,d3 /v0g,ppe is inclined at an angle *p uvqt, /dpn ,(yg l3g0vp3njof $30^{\circ}$ with the horizontal. What is the object's acceleration?

  A 10-kg mass slides down a flat hill that makes k:o )t teut;q6an 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 inclinedqv 9 7gkdfby9v61t eh l2;kc2x 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 planei*ec -rz4 6xzx:w;t.psi r8 ja 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 cra03s(mh(j l2 0ci d f8p-l,g4m hoixkonstant velocity of 6.0 m/s. sc(a,-8hm df0 rxmo3gjhi l 0i(42lpk
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 3 pnh8o- 9 eczj6a )xplze+(xaslides 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 ifbk 95(as hb0down 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. Thhm3r 2v1qc 2kre cable attacher 32 2hr1mkcqvd to the 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 rest on a rough inclined plane t7c 0x ,(ng8 cujx7zr.agzldn;:2 lpk xilted at an angle odzlxrn ;z7l0 g:kxuxcp,c(nj7 ga.8 2f $33.5^{\circ}$ 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 agx -.5jw ) 0*bcbysaavn inclined plane. The angle of incline is gradually increased until the object begins to slide. The g-awa0cs. yb 5bvx *j)angle at which this occurs is q. What is the coefficient of static friction between the object and the plane?