Which of Newton's lawczzh r kncx.ja p0f,9::ne/z(i,de3h s best explains why motorists should buckle-up?

  When you sit on a chair, the re 28qk9u vhu hm62k qng2dkok1p+(6 dmlsultant force on you is

  In the absence of an gwiw 00x; tm*kexternal force, a moving object will

  When the rocket engin8pagcef7 2c w1imhr7 .es on the starship NO-PAIN-NO-GAIN are suddenly turned off, while travelieh r 2w1cgcfi7p 8.ma7ng in empty space, the starship will

  A rocket moves through empty space9 r2k4 s,4koa5oiibk2ux gv ,g in a straight line with constant speed. It is far fri4vis22gx ku k 9r,54o ,bogkaom the gravitational effect 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 mov;-pgw 6* py- 5cs4sojypmr 4huing bus, facing forward, and you suddenly fall forward. You can im*wp - ryph soujm5c py4-g4;6sply from this that the bus's

  You are standing in a moving bus, facing nfye2 ehnx;e :2a/ku0forward, and you suddenly fall forward as the bus comes to an immediate stop. What force caused you to fall forwaku2nhye:n 2;f0aex e/rd?

  A constant net force acts on an object. Describet5x:hc.ao.wptq u2 v* the motion of the object.

  The acceleration of an object is inverselts pbs/ffh6, (y:anc.y proportional to

  A net force F accelerates a mass m with an acceleration a. If the samemr pwqt+k390j41+luyuor c)ic q. os( net force is applied to mass 2m, th+w i 3r1roc40.uco9ml sj+(ykq)pqt uen the acceleration will be

  A net force F acts on a mass m and produces an accei77y b.qb*dn 05pf4ft kpd1v dleration a. What acceleration results if a net force 2F acts on mass in.4*p5b v7yq 0 7dftkb f1dpd4m?

  If you blow up a ballb8/q)pebf0bkw o nv:- oon, and then release it, the balloon will fly away. This is an illukb)-0o/8 :bw fpbqevnstration of

  Two cars collide head-on. At every mom8 kimiqp.lv87 gj0 4iir4khs.ent 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 fisjk.r i lkp4 i0878.im hgq4virst. This is an example of

  If you exert a force F on an object, the force which the object exerts on ytu zzzd7, v,87l l;gd97mugqm0 cosg: ou willcdzzq:ug go7lg,7;9tvzmds 7u08 l,m

  Action-reaction forcesct-uvubq)dal/h n km:0l3,w.

  Action-reaction forcekw.2ci +yrul;s are

  A 20-ton truck collides with a 1500-lb car and causes a kwb.f79l w; ,gcku +u67szxx*h f-trz lot of damage to the car. Since a lot of damage is7x- 6uztgkf s*c lb9rkwz;+f.7x,h wu done on the car

  An object of mass m sits on a flat table. The Earth dixqwn shj6 0u mm5410pulls on this object with force mgjumhnm04 s561qxdw0i , which we will call the action force. What is the reaction force?

  A child's toy is suspended from the ceiling by meansf dprnt,u:1; yyy0s,w of a string. The Earth pulls downward on the toy with its weight force of s: ty,r y, wynpf;du108.0 N. If this is the "action force," what is the "reaction force"?

  Your bat hits the ball pitched to you with a 1500-N instanta2: leaiuhe0 vze 4d:/aneous force. The ball hits the bat with an instantaneous force, wh:eel za4a/vde2hu: 0iose magnitude is

State Newton's three laws/d0t /zdiu ik1l2hq j6+v r5qv.

  Mass and weight

  The acceleration due to gravity tv-r 0;gpikx v6 y c1xlg+4auf6ju( j(is lower on the Moon than on Earth. Which of the fu cgurxka1fivty4+-xv ;6l 6 (g(jj0pollowing is true about the mass and weight of an astronaut on the Moon's surface, compared to Earth?

  An example of a force 7kqt (jnt4j6 6o-s8t9j ymlqa which acts at a distance is

  Who has a greater weight to mass ratio, a person weighin*.od / epctb423k5kgf6rfole a bs,h1 g 400 N or a person weighing ha/5 2.4fcr te,pe1o6s*b3kbdfokg l600 N?

  A stone is thrown straight up. At the top of its pat8 fr8+ f ef5mtzyeb71lgxghmt: 0ak ))h, the net force acting on it xzg0:t a81m h)5tkefem 8f)yrgfb+l7is

  A 20-N weight and a 5.0-N weight are dropped simultaneoyo2mco: l+ b-tusly from the same height. Ib+oclm:2o -y tgnore air resistance. Compare their accelerations.

  A brick and a feather fzva1 nusz74 bmf)g)yr8mp*( jall to the earth at their respective terminal velocities. Which object ex()*fg vammbp8 1 )rzyjs7zn u4periences the greater force of air friction?

  An object of mass m is hanging by a string frohg/bbc5 c-pq7d*, kszwffz z92w l m+(m the ceiling of an elevator. The elevator is moving z*wcds7 k2b,5mz f ( +lp9 wgbf-z/cqhup at constant speed. What is the tension in the string?

  An object of mass m is hanging by a string from the ceiling of an elevator. Th8cbqq5bdq 5d,f cn f8gph9e2uha:9-n;tz (hde elevator is moving upward, but slowing down. What is the tension 55cp;- et:qq9dq hbh8 dn(289 dhbazfun , cfgin the string?

  The force that keeps you ftro)d1( kn1 1g lqp*gq(2o dzarom sliding on an icy sidewalk is

  It's more difficult to start dzn) *ih74i-ba vms7pun)v g 6moving a heavy carton from rest than it is to keep pushing it with constant velocity,sia)hbgn7* -v 4di6z )v mnpu7 because

  A horizontal force accelerates a box from rest across a 7: g4*y9ipeo vyjk g:ehorizontal surface (friction is present) at a constant rate. The experiment is repeated, and all conditions remain the same with the exception that the horizontal force is doubledg veky4ip:9 *7ygje: o. What happens to the box's acceleration?

  A packing crate slides down an inclined ramp at conhu8 a2dt,2n +)gjf fvwm 1u.qfstant velocity. Thus we can deduugd atu)vqj8n2,h +f.2f 1 mfwce that

  A block of mass M slides down a frictionless plane inclined at an angle q with tbmq0417e (kgw jjhfnq l p/cx2c/om40he horizontal. The normal reaction force exerted by the plane on the block44 p0oc/nj b1 q cxj2(7gkmm0/ef lwqh is

  A block of mass M slides down a frictionless n jpe/g d:kttrnj9ue.w0 s ke /,j5(o8plane inclined at an angle q with the horizonese,p:goeu5 j 8n/kjw9r. t/d(j 0tk ntal. The normal reaction force exerted by the plane on the block is directed

  A block of mass M slides49yea io,iv 9;b2fd jm down a frictionless plane inclined at an angle q with the horizontal. The gravitational forciiy em9j b 24dvof,;9ae is directed

  Two toy cars (16 kg and 2.0 kg) are released simultaneously on an inclint:n9h*w fl1jk67o v38wrtbtjf.mwq.ed plane that makes an angle of 30e with the horizontal. Make a sta o8jwff.6.t3 tj w r1kmt:vw7b9qn*hltement which best describes their acceleration after being released.

  An object sits on a frictionless surface. A 16-N force is applied to tf* 7jmr24ac qahe object, and it accelea24rc*7af jm qrates at $2.0 \; m/s^2$. What is the mass of the object?

  A sports car of mass 1000 kg can accelerate from n+ .pk * u,ouq7brjttwi:(abx4(;qpx oh ) 8atrest to 27 m/s in 7.0 s. What is the averabqhuipr:tkx bo 7u + p(.n4)twto(q8 *aa; ,jxge forward force on the car?

  Starting from rest, a 4.0-kg body reaches a speed of 8.0 m/s in 2.0 n8 k67mrulo+q 8e m*5-ftkjb js. What is the net force acting o+mo lnjrk7e*tk q-m 86jbfu58 n the body?

  An antitank weapon fires a 3.00- )n /ht09e6lu kcnkk*+m)ffugkg rocket which acquires a speed of 50.0 m/s after trafuk )0 nu fk)n*c9lm+/hk6etgveling
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 forr.o4be rw (:d* r/j,bgzvmi j*ce that you push a 10-kg mass from revb d4.*ezib*rwg,j r:j(/romst,

  What is the mass of a person who weighs 110 lpku2 65p l3 tidrk0 ob7-twl;wb?

  What is the mass of an object that weighs 250 N on the surface qur3m;9rlh1 uof the Earth where the acceleration dueq u1;umhr r9l3 to gravity is $9.80 \; m/s^2$?

  An object has a mass of 60 kg on the Earth. What is the mass/ 9dycil: ip4 ,5xuone of the object on the surface of the M,9/4xy5u:lp in dio ceoon 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 wei;t)j::whf 6x6yhke cj ghs 40 N on the Moon. The Moon's gravity is one sixth of Earth's. Compare the masses of the objeck y jx;:j 6hhft:c)e6wts.

  Sue and Sean are having a tug-of-war by pulli z/0/s v3bjv0, pu6wjdov ,fstng on opposite ends of a 5.0-kg rope. Sue pulls with a 15-N force. What i0, t6vvb js0, udwp fv3j/oz/ss 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 cecn ;8m9lyf46pn m0g(8ewk(7eb3,jol ekw tstack, and it30mj e(ck pclw 9 7oe,l4 b;nne8g(6tfykwme8 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 elevator. What will jlytc sbc5zv-(j78:y the scale be reading when the elevator i-bj(c5sj8tyczl: y7 vs accelerating downward at $4.00 \; m/s^2$?

  A person on a scale rides in an elevator. If the mass of the person is 60.0* t. zamcu2m6z kg andzmu2* mtc 6.za 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 roqsrqyb; -7f6 ides in an elevator. If the mass of the person is 60.0 kg and the elevator accelerates upward with b qs7or-6fy; qan 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 magnitude (zqo*hk f,w f5of 8.0 N and is directed due north. The second force toward the east has a magnitude of 6.0 N. What i q o*f,fhk5(zws the acceleration of the mass?

  An object of mass 6000 kg rests on the flatbed of a truck. It 2nf-x gm28e7v* ieo4wvet o s8is held in place by metal brackets that can exert a - v*eove2tinwgeosm84x7 f28maximum 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 kgrg f co.1d )p1r.j1fna rests on the flatbed of a truck. It is held in place by metal brackets that can exert a maximum horizontal force .prn1c. ad1f1)rj gofof 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 showpy gc7l.m oz+)n in Fig. 4-1, if M = 0.60 kg and m = 0.40 kg, what is the magnitude of the acceleration of the system? (Ignore friction and the mass of the pul+) pygm.c 7zolley.)

  In the Atwood machine shown in Fig. 4-1, if M = 0.60 kg and m = 0.40qha6w0 di1gz dbd/*,a)ghg)incyg6 1 kg, what is the tension in the string? (Ignore friction and b haza,0))nh id6i6gcqd1/g 1g*y wdgthe mass of the pulley.)

  A student pulls a box of books on x9rydj9,lmx ) (2broe a smooth horizontal floor with a force of 100 N in a direc l,9de9mjx(r) 2ybxortion 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 horizontal floor with a force ofj1 eqdz -uut4n0ad035yfun,y 100 N in a direction of 37.0e above the horizontal. If the maeut uj0n43 n -dz0yu51y,qadfss 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 s:2dw 7y;anngmm b*p,w upported by two ropes as shown in Fig. 4-2. What are the tensions inbm dw m*;n,ag 2y7np:w the ropes?

  In Fig. 4-2, if the tensions in the ropes are 50 N, what is the ma afwdk1x 9wa24ss of the traffic lighdk1w4f 2ax aw9t?

  Two boxes of masses m and 2m are in contact with each other on a fricti r ex(od6 xolt07vr;*aonless surface. (See Fig. 4-3.) What is the acceleration of the more massived6e; *(oat0 o rvr7xlx box?

  Two boxes of masses m and 2m are in contact with each other on a frictionljkf/ x:9 )k vyeldl8xq;-he) less surface. (See Fig. 4-3.) Wd: y k) x lfxkl)e-l;9jhq8ve/hat 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 th6dnebg,a rro)/8l1h xe forward force on the more massive box is F, what is the tension in /8dho6nrxea gl1 ,)brthe connecting rope?

  Two boxes of masses m and 2m are connected by akj4s.qgcixnkt) )u2l j*.td) rope. (See Fig. 4-4.) If the forward force on the m xtj kkstgdqln)i.)2)4 .jcu* 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 ,44p vxy:tt ttwpk0 ms yc4v(+shown in Fig. 4-5. Box I o(04+vsx4t v4t pwpy m yt:,cktf 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 kiv)ov* (tyk(5els y tzva5,er2 xexh,7netic frictions between a 3.0-kg box and a desk are 0.40 and 0.30, respectively. *o,lzyk5esv()e (7x yx hae r,vt 5tv2What is the net force on the box when a 15 N horizontal force is applied to the box?

  The coefficients of static and kinetic frictions fo:jj :kshb0 u/ar plastic on wood are 0.50 and hjs 0b :uk:a/j0.40,
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 surjk3z)cne gkr0):)ru ;fr 2tf rface in the +x direction. It slows and comes to a stop with a constant acceleration of -kz;e)frng2 0r)c 3): jru trkf$2.45 \; m/s^2$. What is the coefficient of kinetic friction between the object and the floor?

  A 10-kg box sitting on a horizontal surface is pullpveu uox2b c5xl:-4/v ed by a 5.0-N force. A 3.0-N friction force retards the motion. What is the accu:l cv45o xvx-be/up 2eleration of the object?

  A horizontal force of 5.0 N accelerates a 4.-z jb* / z;z-q *wetf5evix(ci0-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 iqkuo6+a,a tkkt,8dr ms12nf 7s given an initial speed of 10 m/s. It slides 50 m on the ice before it stops. What is the coefficient of kineticua+oattk f2qdk,7n k1rs,68 m friction between the puck and the ice?

  During the investigation of a traffic 6kp8uz9:gn/k2:ip kwp anl 2atvdv .9 accident, police find skid marks 90.0 m long. They determine the coefficient of frict p z2vnp 8kg.9 p:9i2akdw /l:vanu6tkion 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 mlb01jx)0;a. j-wb9 qzd o 3vwvm- kgnl 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 the boxes is jv;l-ok0gb) 1mjanv0 l d3wbq.-xw9z 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. (Seepuy; 4p7 ma;wr,uq)ko Fig. 4-6.) The surface between the more ;4rmuu),owpy k;aq p7massive 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 frictir rn2;m,okk :eonless inclined plane. The plane is inclined at an angle okrm 2rn :e,;kof $30^{\circ}$ with the horizontal. What is the object's acceleration?

  A 10-kg mass slides down : pdu:l(3ex1x 4;lu3 tpzafxoa 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 pr7b qu61 zs-dolane 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 a mjc0 p0nq.ot.uw /.fyt 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 sr) inazg pdpa5c:0.c(d8 p4 udirectly down an inclined plane, at a constant velocity of zp 5.pcp0 r4(i:an sc dg)ua8d6.0 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 slgu 4dxe5,e5;m quf/m7r;,hpa -l pnndides 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 down ekbc; o2 z9dfll8qb: :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. Tqk 0-sb*v2wtht,hs( hhe cable attached to the log makes an angle of (,hh kbt2w* -tqhs0sv$30.0^{\circ}$ 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 hg-d0ni wg).jan anglehggjd. 0w-) in of $33.5^{\circ}$ 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 inclin8vkbg wg*nk2w tqa3;,ed plane. The angle of incline is gradually increased until the w2wk abnv*q;t8g,3kgobject begins to slide. The angle at which this occurs is q. What is the coefficient of static friction between the object and the plane?