Which of Newton's laws best explains why motorists should buckle-up;-6- jeu ) e(vopcqeet bng):q?

  When you sit on a chair, the resultant force on you. zg6 r vgr),24mr5p+smayzem is

  In the absence of an external force,gx3av 235t six a moving object will

  When the rocket engines on the starship s8rml8iu bb+87loaj tf9:n+oNO-PAIN-NO-GAIN are suddenly turned off, while travs8anm+ fuo+97jibt r88oll: beling in empty space, the starship will

  A rocket moves through empty space in a straight line w ygo*4g:22* idb qzvp5zbgk0 1sisl (fith constant speed. It is far from the gravitational effect of any star or planet. Undo04 p ls1 z d2fvig5y:g2qz (kgbi*sb*er 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 fuo;i a7/zr(wdzyb1 ).ye ztd1all forward. Yot 1w )1i/d;yur oybe.dzz 7z(au can imply from this that the bus's

  You are standing in a moving bus, facing forward, and you suddenly fall feao1(-)sv ,jaa0 ul fnorward as the bus comes to an immediate stop. What force caused you to fall )as1e jlafanu0-(vo, forward?

  A constant net force acts on an oige8 :avvy(*lbject. Describe the motion of the object.

  The acceleration of an om1d7t+5 -y: i2iw8 nnpeij8tq ) keqbvbject is inversely proportional to

  A net force F accelerates a mass m with an ac;5*w eozf oan+i*ya /wceleration a. If the same net force is applied to mas y /+o;*wwa5 oeaif*nzs 2m, then the acceleration will be

  A net force F acts on a mass m and produces an accelerattwfsg-5e0 l cc9a*ll6yu 0ba4ion a. What acceleration results if a net force 2F acts onlucs 0cef0-wla9 ylb4g*6a 5 t mass 4m?

  If you blow up a balloon, and then release it, tbyte-bgcbw:9 6 m +8uihe balloon will fly away. This is ab9t e8mib:wbgy-6 c+u n illustration of

  Two cars collide head-on. At every moment during th p1 3voc/tnmngd.f)im ihdjm5 6h39g,e collision, the magnitude of the force the first car exerts on the second is exactly equal to the magnitude of the force theif3mgo h/.51v hn,dpjn9 td)m gc3im6 second car exerts on the first. This is an example of

  If you exert a force F on an object, the force which the objcx- -pcsj1gwja0 yy6: ect exerts on you wilsj py1jc6 0-gwxy -:cal

  Action-reaction force np2)7ca4 alhks

  Action-reaction forces jw-udgt -fzse7-vqrp 6i/3* v are

  A 20-ton truck collides with a 1500-lb car and causes a lot of damage to l-gd;hqmpnhnnc,; d a; ;. /jnthe car. Since a lot of damage i pd/nnn;hc -am.h d;gj,lnq ;;s done on the car

  An object of mass m sits on a flat 5m zy(x*oo/x b p9)2dhhu r ele9mq84etable. The Earth pulls on this object with force mg, which we will )e5 z 4mqrudb(2m 98el9oo/yex*xhhpcall the action force. What is the reaction force?

  A child's toy is suspended from the ceiling by means of av,ypeg938o 7*qddz a j string. The Earth pulls downward on the toy with its weighdyveop 9g3qza 87,*jdt force of 8.0 N. If this is the "action force," what is the "reaction force"?

  Your bat hits the ball pitched to you with a 1500-N instantaneous forck ocimz8-:,b ye. The ball hit,8 kbo :-imzcys the bat with an instantaneous force, whose magnitude is

State Newton's three lawsb 3yr8xoso) x+.

  Mass and weight

  The acceleration due to gravity is lowe .(yaus(y 5kwyr 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, c5ka uyw.yy s((ompared to Earth?

  An example of a force which acts at a distance i9p)qg 4xk7dof s

  Who has a greater weight to mass ratio, a person weighiwkh e0 z4rj 9,;wxmyh3ng 400 N or a person weighi 0yrwe;wkjh3z, m4x9hng 600 N?

  A stone is thrown straight up. At luu;p(y+gvgtuyp tt/.x. 85w the top of its path, the net force acting on it it+p ./v85wt.uty y(gg x;upuls

  A 20-N weight and a 5.0-N weight are dropped sirkoq)we t+p(9y-m fu;f7j vf 5multaneously from the same height. Ignore-tp( m9j wuyov;5ekfr7fq+f) air resistance. Compare their accelerations.

  A brick and a feather fall to the earth at their respective terminal vew 8.u86lquikw locities. W 8.kql8ui uww6hich object experiences the greater force of air friction?

  An object of mass m is hanging by a string f5 mys4r j:o2f wdz1(ourom the ceiling of an elevator. The elevd5s:zom(rfw ou124j yator is moving up at constant speed. What is the tension in the string?

  An object of mass m is hanging by a string from the ceiling 5z*j2rx5oejiua1, qe of an elevator. The elevator is moving upward, but slowing down. W qzxe,5* ie2jo1aur 5jhat is the tension in the string?

  The force that keeps you from sd / s; julobc.)*fo-u s*:gwooliding on an icy sidewalk is

  It's more difficult to start moving a heavy carton from rest than it is to keepmnskc( 4u5c:u .6 cyce pushing it with constant m.6suyc(k nuc5ce :c4velocity, because

  A horizontal force acceleratb3 d0o 1i jsh5v*fpps0es a box from rest across a horizontal surface (friction is present) at af3s0pispob d15h *0vj 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 slides down an inclined ramp at constant velociq4hb, i isnqsg/1sv1( fsi+x *ty. Thus we can dedgssqx ( +qsfin 1bi hv4s1*,i/uce that

  A block of mass M slides down a frictio3ewq tt t.z(4+ j/kymhjw2i 6inless plane inclined at an angle q with the horizontal. The normal reaction force exertiw.m4qi( h6ye tjjz+2/3 tkt wed by the plane on the block is

  A block of mass M slides down a frictionless plane inclined akw yj7csiap6s83t h-r/2kl6 w t an angle q with the horizontal. The 832aikjkl ys67wtsp r-/w h6c normal reaction force exerted by the plane on the block is directed

  A block of mass M slides down a frictionless plane inc uyl.5ax2giq.* :dgarlined at an angle q with the horizontga . .rxliy*du52qa:gal. The gravitational force is directed

  Two toy cars (16 kg and 2.0 kg) arq)w j2nmcu5 ac 0hb5t 4f3g.mge released simultaneously on an inclined plane that makes an angle q)cajmh. 0f mt4guwb52c5gn3 of 30e with the horizontal. Make a statement which best describes their acceleration after being released.

  An object sits on a frictionless surface. A 16-N aa aby;p2y24 qzh ym1lsy 9x2e,b;q2hforce is applied to the object, and it acceleratesy qyezy2bqh9 p4a;2ax;ls2bah1 y2m , at $2.0 \; m/s^2$. What is the mass of the object?

  A sports car of mass 1000 kg can accelerate from rest z 7fccm*q ;3jgc3tm.lto 27 m/s in 7.0 s. What is 3 q3.c c7mlctg*fmj;zthe average forward force on the car?

  Starting from rest, a 4.0-kg body reaches a spee ,bodur3p5dn,+o ale9o v1k .5eb pi(wd of 8.0 m/s in 2.0 s. What is the net force ac,kedrv p ew5(53bbopn .,oadl+9 iu1oting on the body?

  An antitank weapon fires a 3.00-kg rocket which acquires a speed of 50.0 m,:pia; cs:7kwd 2mn3q8-sajdn . gmje /s after.d ,nacag2mjpen7:k8dqi ;s3s: m-wj 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 m:el r via8seuezr567;l5i+ pmass from rest5r r m:i;zal l+8eve6 sieu75p,

  What is the mass of a ab q5es p4i)0 (gvr7cyra.n* nperson who weighs 110 lb?

  What is the mass of an object that weighs 250 N on the s/;q 50 tkhfgs hb5;njf(vt 1kwurface of the Earth wherj ;t s;b(5tk/0 ghfwvqhn 51fke the acceleration due to gravity is $9.80 \; m/s^2$?

  An object has a mass of 60 kg on the Earth. What is the massiph l 2n:8 lv6m+fso*r of the object on the6 *:orf2m8l +shv nilp surface of the Moon where the acceleration due to gravity is only 1/6 of that on the Earth?

  Object A weighs 40 N on Earth, and object B weighs 40 N on the Mq:f3j. 1(rwtr)ae(e6k ,; hfk gxsc ukoon. The Moon's grav: e rak kff,jk36s1xwh( . ce(;rtqg)uity is one sixth of Earth's. Compare the masses of the objects.

  Sue and Sean are having a tug-of-war by pulling on ow bf )v-p6aapn v53fa*pposite ends of a 5.0-kg rope. Sue pulls with a 15-N f36)p5av nfb fw-a*pvaorce. What is Sean'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 acts on the 9oml,i m s2i1ostackmosl9o1im ,i2 , 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 eleva zpxizja8rh)7:is 2f6tor. What will the scale be reading wh6rixh )2a:zfz87 ipsjen the elevator is accelerating downward at $4.00 \; m/s^2$?

  A person on a scale rides in an elevator. If thehdql+32qbi7p1wh 0w s mass of the person is 60.0 kg and the elevator accelerates downward+ i3 bslqhp dwhw720q1 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 m 9) ),f:gcgit ogzc z2k3kg-yiass of the person is 60.0 kg and the i,)2yg )ki-kt oc3gcfz gg9 :zelevator 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 mass. One force hrgyq v:3ug4x0lyhs6cj)5d: 1 a 6fggb as a magnitude of 8.0 N and is directed due north. The sj53gru fcl:xgya gg)s 0q dvb6:h46 y1econd 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 truck. It iskieve mbc bq/ukw062( i/9j z8eclf7( 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 7ckb f9ze/j v eilb/cq26ke8mu(0 w(i is not to slide forward into the cab?

  An object of mass 6000 kg rests on the fe d5ks 9p(f+f+ 8qrzk cl2ee1rlatbed 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 (k 12qzrp e+kl85ce9e sdff+rtraveling 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, whno; f ug8o.mn(at is the magnitude of the acceleratio(o 8nmno;.fug n of the system? (Ignore friction and the mass of the pulley.)

  In the Atwood machine shor9a;-hsvj8x yslm1wh /2pw b;wn in Fig. 4-1, if M = 0.60 kg and m = 0.40 kg, what is the tension in the string? (Ignxh pw v;s;jwsy2a/ml 9bh-81rore friction and the mass of the pulley.)

  A student pulls a box of books on a smooth hcjndla/45/4xdg mcjx2 1c4a m orizontal floor with a force of 100 N in a diremcdjx 5xn4/m 2d c jga414l/acction 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 s zi i*xp5e9r.zmooth horizontal floor with a force of 100 N in a direction of 37.0e aboveix*eri z5. 9pz 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 100tl).8a* *39 djsq y o0g) 1nuzwubafit N is supported by two ropes as shown in Fig. 4-2. Whlw8ud)n.*zf* a 03i tjobs)1 9uaqgytat are the tensions in the ropes?

  In Fig. 4-2, if the tensions in the ropes are 50 N, what is the mu 4bjhtln /m+vj, ozzp8k9 +(kass of the traff zv+ /ju(8j4khbo 9zptl+k ,mnic light?

  Two boxes of masses m and 2m are in contact with each othw jj3bg;s ( z 6in/n4 .9nvlyqw.8ceqoer on a frictionless surface. (See Fig. 4-3.) What is the s/lgzq(noi n4vyjn qbc3 ;. e9jw.w68acceleration of the more massive box?

  Two boxes of masses m and ;bvuctl ;f:0ogy 4 ,gf2m are in contact with each other on a frictionless surb;fo v4t,g: l;0gcuyfface. (See Fig. 4-3.) What is the net force on the more massive box?

  Two boxes of masses m and 2m are connected ie3 zm8/8pt gvf)5z wrby a rope. (See Fig. 4-4.) If the forward force on the more massive box is F, what i)8emzfg tz /53p wriv8s the tension in the connecting rope?

  Two boxes of masses m and 2m are connected by a rope. (See Fig. 4-4.) If the vys 5:(rk ut3bforward force on the more massive box is F, what is the yu strk5(3b: vacceleration of the less massive box?

Two boxes are connected by a cord running over a pulley as shown in Figwephc*9q4 n,zyq -4ed. 4-5. Box I of 4ed*9nqp4we-qhzy, c 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 -wm* nlnrdi.7vjf1p9:4v qwk 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 aprlkn-f1 n dm4w :.9w*j7 vvpiqplied to the box?

  The coefficients of static and kinetic frictions fouqi,4mx zao 90r plastic on wood are 0.50 an9om4z ia u,q0xd 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 lev6.qxc8 (rpvuy el surface in the +x direction. It slows and comes to a stop witq8( xc6yu.pvrh 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 horizontazi u6vyr+ n.l.k /3c+iyna5ujl surface is pulled by a 5.0-N force. A 3.0-N friction force retards the motion..j+y .v3iy 6z5nalcuir/ kn +u What is the acceleration of the object?

  A horizontal force of 5.0 N accezrte. l*) 0glelerates 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 gvv 9 44bt:jri6 )gn*yrwcbc*sw*3lwh iven an initial speed of 10 m/s. It slides 50 m on the ice before it stops. What is the coefficient of kinetic fvwn93h vw4rbr:g*4jcs)y *6 *icwt lb riction between the puck and the ice?

  During the investigation of a traff: 7 wd8nzt3losic accident, police find skid marks 90.0 m long. They determine the coefficient of friction between the car's tires and the roadway to be 0.500 for the prevailing conditions. Estimate the speed ofz7:3lst d nwo8 the car when the brakes were applied.

  Two boxes of masses m and 3m are+wa -6-j6gnt 2 iqqaij stacked. (See Fig. 4-6.) The surface between the more massive box and the horizontal qa6i+i6 gjn - wtj-aq2surface 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 stacked. (See Fig. 4-mkje8,-f:i o2id n g6p6.) 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 is the coefficient of static friction between the boxesodp-,8mie : kin6jf2g?

  An object is on a frictionless inclined plane. The plane is in- z 49j4iel10lbgw; br3 nxhejclined at an angle of-wlr9l;e3 4b eh10izxgjj nb4 $30^{\circ}$ with the horizontal. What is the object's acceleration?

  A 10-kg mass slides down a flat hill that makes (f94-ud,t* rxhycg7r 5 meha uan 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 aeq2.q.juh (ef + cgfe6;m;q obngle 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 plak4)c- vi2m3*g)h ccz9 zbrsmcne 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 constabju3.3n cvy)vuy5 h.gnt velocity of 6.0 m/s.n3 y3..cu5jhvbv)yug
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 r:e0 u10qm5juab1 lx m,kxq wey+otj./ ough $37^{\circ}$ 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 a r 619cazck z6*hr g9pjjtiw18 oough $37^{\circ}$ 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 alon x+ ltj +smpea4x(1-tqs/sz:sg a rough surface. The cable attached to the log makesqjztsp s( +-xaxe1 l+m:t/s4s 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 tilted at t 5)bd8qxha1t-o 0p47 ltfjjsan angle of tjdt4xpj)b1 aol 5q07h-f8t s$33.5^{\circ}$ 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 inclwn-s*8(wvf+ps+, 0ezs r el fgined plane. The angle of incline is gradually increased until the object begins to slide. The angle at which this occurs is q. What is the coefficient of static friction bet*f rsznvws-p(s8+l0+ ge , wefween the object and the plane?