Which of Newton's laws best explains why motorists sxd9q zc r, atn+.vx9/hhould buckle-up?

  When you sit on a chair, the resultant force )f k-88o tsnjs35wedn on you is

  In the absence of an external force, a moving o wutb8r/ xkysd0lhp: :(cr/59cwv;h ybject will

  When the rocket engines on the star*k7 xpjl xq3,rship NO-PAIN-NO-GAIN are suddenly turned off, while traveli*xxrpq3 lj,7kng in empty space, the starship will

  A rocket moves through empty space in a straight line with constiyxha288 d9 eaant speed. It is far from the gravitational effect of any star orh9eixa8 28ayd 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, fac9r.*qv k jj:6lw mdt)/)yihmring forward, and you suddenly fall forward. You can imply from this thjvl mit md:wh j6 k.qrr9*y/))at the bus's

  You are standing in a moving bus, facing forward, and e cx5u03t 1ao pet-b6zyou suddenly fall forward as the bus comes to an immediateab0t-o1utx c3e6pe z5 stop. What force caused you to fall forward?

  A constant net force acts on an object. Dried 7+l61nk-uwi7pb s 8 z2d7jq bq52h xk9caescribe the motion of the object.

  The acceleration of an object is inversely pr.g21k,3 ft4ijx w smznoportional to

  A net force F accelerates a mass m with an acceleration a. If the z jzo75bj7nz rc n*r5p/s 0:kesame net force is applied to mass 2m, then the accelez snrcjnb7z5:57z0rjoe/ k*pration will be

  A net force F acts on a mass m and prog+n2 w 4fr5lpeduces an acceleration a. What acceleration results if a net force 2F acts on mal5fpge2 nr4 +wss 4m?

  If you blow up a balloon, and then release 3ujh *vq.;qii it, the balloon will fly away. This is an illustratih.qvji3 q*u; ion of

  Two cars collide head-on. At every moment during 1sf gqe+/ 5pzdthe collision, the magnitude of the d+p/fg5 1sqze 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 of

  If you exert a force F on an object, the force which the object exerts on y qr7r) ;mc44ifurp m)xtp,8vlou wix ;imvpm 84rf,74qlc r)tp ur)ll

  Action-reaction forces7 j;y8qebzfq(nu*:se a 0f4qj

  Action-reaction forcea+ eokd.g13 wqs are

  A 20-ton truck collides with a 1500-l*ff 3 fuio+rr-8pl-h:h z6ojnb car and causes a lot of damage to the car. Sin8 6+z :f*of3--nhjphif r roulce a lot of damage is done on the car

  An object of mass m si4 5dqi3 ytfs6 o;hjpx0ts on a flat table. The Earth pulls on this object with force mg, which we will call the ys05p;foj4 xqh36d t iaction force. What is the reaction force?

  A child's toy is suspended from the ceiling by means of a string. The E,,qz1s;yv dx( fzbw fq0r, mg)arth pulls downward on the toy with its weight force of 8.0 N. If this is the "action forg(z01,rxb,m;v,sf qf )dyq wzce," what is the "reaction force"?

  Your bat hits the ball6hup4i(6clfcxi, 8gsh- o*ub pitched to you with a 1500-N instantaneous force. The ball hits the bat with an instantaneo clx -sf8o,guc6hi( hbui *64pus force, whose magnitude is

State Newton's three law:4o sog bqqcibi ) 0a07-8ybiss.

  Mass and weight

  The acceleration due to gravity is lower on the Moon than on Earth. Whicap e+59f/4/ 9dj6qyyne jlxt yh of the following is true about the mass a ln9 q6j//a tpyye+5e 49fyjxdnd weight of an astronaut on the Moon's surface, compared to Earth?

  An example of a force which acts at a distance ismdgz2fw:,y kk+ - :aitkpm-r 5

  Who has a greater weight to mass ratio, a person weighing zs ;at9vwjvr h5 2v3*g :qan.a400 N or a person weighing 600 s* vj2vwn v:ga5 zr.aq h3a9t;N?

  A stone is thrown straight up. At the top of its path, the 6+,d1+3jhgftjn q wcw yz3n n.net force acting on itwjc,.yg+n zwt1qfjn 33hnd+ 6 is

  A 20-N weight and a 5.0-N weight are dropped simultaneously from thexu9jhkht4;ejij-/3s same height. Ignore air resistance. Compare their a9sh;ijh ekt /3j j-4uxccelerations.

  A brick and a feather fall to the earth at their respective terminal velociti+ k z.ld6okcv0es. Which object experiences the greater forceldkk o6c0 zv+. of air friction?

  An object of mass m is hanging by8(:v+a a)znbwvpzr;-cej l- e a string from the ceiling of an elevator. The elevator is moving up at constant speed. What is the tensiojne-zb v8: a+cr-)vplew a;(zn in the string?

  An object of mass m is hanging by a string from the ceiling of an elevator. Th)oh4f;9 y4s ; p6tljf6njnt ife elevator is moving upward, but slow4tof snp;jif 9ynj;6h)l 4 f6ting down. What is the tension in the string?

  The force that keeps ,pz -oqjmq9jp15 bp8 g94cglz you from sliding on an icy sidewalk is

  It's more difficult to start moving a heavy carton from e rqb k7:.pa/0eosdh/rest than it is to keep pushing it with conssr /doeph0b/k .7 qe:atant velocity, because

  A horizontal force accelerates a box from rest t 9ut1dhc (,myacross a horizontal surface (friction is present) at a constant rate. The experiment is repeated, and all conditions remain the same with the exception that the horizontatd( y9,tu1hcm l force is doubled. What happens to the box's acceleration?

  A packing crate slides down an inclined ramp at constant velocity. Thus we ca6 zdkn-:)stcmn deduce thamd):-6tcznsk t

  A block of mass M slides down a 1 y z(f7pd+.lbh vikt +(-kstzfrictionless plane inclined at an angle q with the horizontal. The normal reaction force exerted by the plane on thklydbif k(z+.1s t-p+z v(7t he block is

  A block of mass M slides down a frictionless plane inclined at an angle q wyspt*y0z)q2 yiz(( o jd b9/q(or 2qffith the horizontal. Thefis( 0bpoq9 oyf/y()jzz tdr*qy2( q 2 normal reaction force exerted by the plane on the block is directed

  A block of mass M slides down a frictionless plane inclined at an ang/2ba ;9 wdvikejy: lcn )ho;8t*r ur9rle q with the horizontal. The gravitj8/r)kwdhyueb arrntv 2o; l 9i*9 :;cational force is directed

  Two toy cars (16 kg and 2.0 ktt4qnwz8h b ir887f0s g) are released simultaneously on an inclined plane that makes an angle of 30e with the horizontal. Make a statement which best describes theii0h 8z7 8w8ts4brnfqtr acceleration after being released.

  An object sits on a frictionless surface. A 16-N fogo. rt, a;nrc+rce is applied to the object, and it acceler; ctr+.aorng ,ates at $2.0 \; m/s^2$. What is the mass of the object?

  A sports car of mass 1000 kg can acwyp 19k qwx06if k7waabr:x-4 celerate from rest to 27 m/s in 7.0 s. What is tw 0b6akawk1w4 :fxrx -y pi7q9he average forward force on the car?

  Starting from rest, a 4.0-kg body reaches a speed of 8.0 m/s inthzt2fb; x 2brz0,rw * 2.0 s. What is the net force acting otbfxrt; b h2*zr0w ,z2n the body?

  An antitank weapon fires a 3.00-kg an*mq muwvc6 *t *9l/ cwylj*-rocket which acquires a speed of 50.0 m/s after travelmvmu n9 cll/w* **-6yqwctaj*ing
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 tc ,xkt5a+ros u,)m5q mhat you push a 10-kg mass from re5,+mar5k oqm,x ct)usst,

  What is the mass of a pesklt 5q;) 980l vsiwglrson who weighs 110 lb?

  What is the mass of an object that weighs 250 N on the surface of the Earth n(4ij5zo0.cq ewqrw -ry 1hb-hev +6i /ejx h3where the acc h4-0c.i3o1/exj hwr5q iq(y+n-je v6bhe w rzeleration due to gravity is $9.80 \; m/s^2$?

  An object has a mass of 60 kg on the Ea8bu yts2a7-,v /cf+fvlquc(c2b9 vio rth. What is the mass of the object on the surface of the Moon where the acceleration due to gravity is only 1/6 of that on thes c 7vof, b2lqac-v9u fbcu8v iy/t(+2 Earth?

  Object A weighs 40 N on Earth, and7r9g*hxoh lz g+,n o1h object B weighs 40 N on the Moon. The Moon's gravity is one sixth ofglg1nh r*o,ho9h 7x+ z Earth's. Compare the masses of the objects.

  Sue and Sean are having a pq(. eko)g 0j,frgw5 stug-of-war 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 tow owjk pfgr q,)e(gs0.5ard Sue at $2.0 \; m/s^2$?

  A stack of books rests on a level frictionless surface. zin; 9taksg, cp vm(er:0*nti+f 8ww5A force F acts on the stack, and it accelerates ak 5in ntg a;*rs,zf 0wtiwc8v9:(pm+e 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 (k;qp mln. -j*dew6p uelevator. What will the scale be readkm. -jn*q(p lp6w; ueding when the elevator is accelerating downward at $4.00 \; m/s^2$?

  A person on a scale rides in an elei8 gvq+ld v,/xvator. If the mass of the person is 60.0 kg and the elevator ac 8l+dv/ ,ivqxgcelerates 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 tum*1ji*ffj/3 ohxe 2bdfvv- :8h ui,dhe person is 60.0 kg and2xm8u*if*b, v d1ivh:e3uho /ffdj-j the elevator accelerates upward with an acceleration of $4.90 \; m/s^2$, what is the reading on the scale?

  Two horizontal forces act on-ke xib7d /:xk a 5.0-kg mass. One force has a magnitude of 8.0 N and is d-7id k/xe bk:xirected 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 flat(w dguck/hng m1 ifp c/3+j2*tbed 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 distance if the load is not cw pdf (muich+1tj3*ng/ g2k /to slide forward into the cab?

  An object of mass 6000 kg rests on the flatbed of o;vk gembjz hn n9/;9. 6rfflc,)vq*m a truck. It is held in place by metal brackets that can exert a maximum horizontal force of 9000 N. Whg*.;kh/ejflm 9omn;6f, c zn9qv)rvben 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 machinerl*)kwy1 bdh0)oj d8p shown in Fig. 4-1, if M = 0.60 kg and m = 0.40 kg, what is the magnitude of the acceleration of the sys 1k* j)y0d8)h rlodpwbtem? (Ignore friction and the mass of the pulley.)

  In the Atwood machine shown in Fig. 4-1, if M = 0.6jj 0ty6sts2wwkerdl t 1f:*(h06:d sh0 kg and m = 0.40 kg, what is the tension iw s2(ttywhkl0: jtd6hed0*:f ssr61 jn the string? (Ignore friction and the mass of the pulley.)

  A student pulls a box of books on a smooth horizontal floor wi0/gsi ipw9y /wth a force of 100 N in a directiog sp0w9w/ y/iin 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 smooth hor/*9f iaovqxt5 qju :mh()1s 5plxdw-uizontal floor with a force of 100 N in a direction of 37.0e above the horizontal. Isflw) v/*qqm:h (5da5tpu j9u-1x xoif 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 s,s(s;n7 zh 8e:9ou d p7nwalazhown in Fig. 4-2. Wh;nd97npoz(ssa7,z: a w lh8ueat are the tensions in the ropes?

  In Fig. 4-2, if the tensions in the ropes ) agkn yi(vx;3are 50 N, what is the mass of the traffi ;y3gxvia )nk(c light?

  Two boxes of masses m and 2m are in contact with each other ou pzhk,zc gqrn7 8-.l bg2vl./n a frictionless surface. (See Fig. 4-3.) Whr-g vnc.,zg .hulb7qk 82zlp /at is the acceleration of the more massive box?

  Two boxes of masses m and 2m are in contact with each other5q- ee;po/i /l.p.svtowo gbsf .*0 rv on a frictionless surface. (See Fig. 4-3.) What is the net ogsbetw i .qo.f*5ovse;p v/lp.-r/ 0force on the more massive box?

  Two boxes of masses m and 2m arkkfk+a2l 2naw 4n(,g te connected by a rope. (See Fig. 4-4.) If the forward force on the morakf k,+(t4nn2wg lak 2e massive box is F, what is the tension in the connecting rope?

  Two boxes of masses m and 2m are connrc/1wxs*u h d8dco7q 3ected by a rope. (See Fig. 4-4.) If the forward force on the more massive box is F*o3d8us rw hx1c/ q7cd, what is the acceleration of the less massive box?

Two boxes are connected by a coe t /nvp w.g-ii9km j,y),8qfard running over a pulley as shown in Fig. 4-5. Box I nami.i,gyq)- f9 kjv,wet/8pof 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 frictidahf b:r 45f2gay1zj0ons between a 3.0-kg box and a desk are 0.40 and 0.30, respectively. What is the net force on the box w0f51 gr:af a2djbzh4yhen a 15 N horizontal force is applied to the box?

  The coefficients of static and kinetic frictidg0z mp ( 6nxbve) 5fb/:xfgcyu*2cj.m-7kthons for plastic on wood are 0.50 anj)buf*. mkbg5 vecn zdxxhc-p (t2 g0yfm7 6/:d 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 comesi,4 b7 6gbnseo to a stop with a constantne7b46s ,io bg 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 su9 qq d9gl9q5cqrface is pulled by a 5.0-N force. A 3.0-N friction force retards tgc995q qdqql 9he motion. What is the acceleration of the object?

  A horizontal force of 5.0 N accelerag7pc ;fyn(;uk o15lzmtes 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 gamet6 lca 4 *onfqo,(wc g+eb+:r(cgksb3lz2 cx6, a puck is given an initial speed of 10 m/s. It slides 50 m on the ice before it stops. What +l6xzf 2 n3ql ,4*was(ero(gc:b+ctkc6c bo gis the coefficient of kinetic friction between the puck and the ice?

  During the investigation of a traffic accidentxnh ; fm3,xh6 qe)y,wl, 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 of the car whenq6le)y hm,x ;f 3nwxh, the brakes were applied.

  Two boxes of masses m and 3m are stacked.t (93i)gqqkl me)hwa6 (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)ge qh)(qm 6ialtw39 k is the static friction force on the less massive box?

  Two boxes of masses m,2vqemu /tyu / and 3m are stacked. (See Fig. 4-6.) The surface between the more massive box and the horizontal surface is smooth and the surface between th2,/ue yt/muvq e 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 plane is inclined at an angh:-cbpn9 y7* z*:b4uqvegr i :(lsefele fin*4c7- ( l: eqph* yguez:9be:rbvsof $30^{\circ}$ with the horizontal. What is the object's acceleration?

  A 10-kg mass slides down a flat hill that m b/bc2 *uvmih*akes 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 s 6,rrfk 1* fgt)5jmqtvmooth 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 plane tilted at an angle oix - v;yve z.8job +vr7i.ywe.f $35^{\circ}$ 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 do1 e-r zi lbp-h f16cyb-y,f4irwn an inclined plane, at a constant velocity ofyhf-ceilf - 46b 1z-y,p1brir 6.0 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 rx3d a1myjblcgs 06-,aough $37^{\circ}$ 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 )w6ql,uj8 owfa 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 weighu33*k/ o) kdcgv b/oxosbb((ming 500 N along a rough surface. The cable attached to the log makes an axcoo *mg3(sb/() odb vku kb/3ngle 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 plank.7lqp (f9eep3c7vpce tilted at an angle oce(f9c e. pp7p3ql7kvf $33.5^{\circ}$ 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 inclineb(8usu0m. ev * hf6:2ir yshu4k ga-il is gradually increased until the object begins to slide. The angle at which this occurs is q.y a 2e.kbs*mu ril4h(08ifv:u guhs6- What is the coefficient of static friction between the object and the plane?