Which of Newton's laws best expl n0x) 9u89sghpj 8a ylyw;evs9ains why motorists should buckle-up?

  When you sit on a chair, the resultant force on you 9nhk2x8axu m/dt.+bc is

  In the absence of an external force,1eszw; qfq vo4a-*sp )/tl3 .pg7ocgt a moving object will

  When the rocket engines on thef.xydsslm4np;dqd )qm(d 5( +vr gj3; starship NO-PAIN-NO-GAIN are suddenly turned off, while traveling in empty space, the star) 3jnsvs5m + dddxrqlp; 4( qfydm;.(gship will

  A rocket moves through empty space in a straight line with constant speed.;2d-i,qhlq oy It is far from the gravitational effect of any star or planet. Uh2q;ild -qoy,nder 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(y: yniu g,.gy fall forward. You can imply froy,i:gnug. (yym this that the bus's

  You are standing in a moving u* (gap0,jmo(v bjub2bus, facing forward, and you suddenly fall forward as the bbpu(u bjmo (a*,v 02jgus comes to an immediate stop. What force caused you to fall forward?

  A constant net force a* r n3-t2+lwlhoj1uc icts on an object. Describe the motion of the object.

  The acceleration of an object is i yc( kqdk ;8n,c+shjh2iy0jw9nversely proportional to

  A net force F accelerates a mass m with an acceleration a. If the same nevp; l or *+xsqe ;5qttu526avqt force is applied to mass 2m, then the acceleration wilr5pqx5oe2vs ;la uvq q*tt6;+ l be

  A net force F acts on a mass m and produces an acceleration a. What accelerat8l6xz 5wzx cnnl) u/b66 )pztr x0j7nwion results if a net force 2F acts 7zj8 )xlctwn6n6p bzwxx) n ur0l65z/on mass 4m?

  If you blow up a balloon, and then release it, the bald-;mzubw t4r95igx ;7r8tpu vloon will fly away. This is aniv4w;8 p z 7uttrmbgdx;-r95u illustration of

  Two cars collide head-on. At every moment during the collgv :p)szply.4ision, the magnitude of the force the first car exerts on the second is exactly equal to the magnitude of the force the selvz g s4.y:p)pcond 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 you wnm0q / me24c9 fvdw2ra-olj b:i: w 2c-9dbmq4ej2nam/ lfv or0ll

  Action-reaction forc;1t 3y 5c h.b cljvhasar*8f9ses

  Action-reaction forcec /t0xzt+kf a wo.wh/)s are

  A 20-ton truck collides with a 1500-lb car and causes a lot of damage to the car ;b+4r54fgss cfd uv qi6j f0t-lg,)vs. Since a lofq4 ;cs+fjdsrgg ,t0 v- bu vfisl56)4t of damage is done on the car

  An object of mass m sits on a flat table. The Earth pulls on thi sxubpb: 57.jcs object with force mg, which we will call the action force. Wh. cb pbjsx5u7:at is the reaction force?

  A child's toy is suspended from thej.cs fg 36rse- ceiling by means of a string. The Earth pulls downward on the 36rjs-efsg c. toy with its weight force of 8.0 N. If this is the "action force," what is the "reaction force"?

  Your bat hits the ball pitched to you w-s6wf3mqxumx qr4+)ic /d .bcith a 1500-N instantaneous force. The ball hits the bat with )fwuq6mi3.qx ds -x/rb4c cm+an instantaneous force, whose magnitude is

State Newton's three l q-7odg3,i spnaws.

  Mass and weight

  The acceleration dueyh-fyp)1 x: ,m.yrf dw to gravity is lower on the Moon than on Earth. Which of the following is true about the mass and weight of an astronaut on the Moon's y1d- yfpm:rhf), y. xwsurface, compared to Earth?

  An example of a force which acts at a siw6 ah misx5z-c4*( hdistance is

  Who has a greater weight to mar)+t-h t3i zdallty7 6ss ratio, a person weighing 400 N or a person weighing 600 N?7h+ d 6a3ylztt)lti r-

  A stone is thrown straight /0ktu; emd6afup. At the top of its path, the net force acting on it is0 k;fdmt/au6e

  A 20-N weight and a 5.0-N wei7)id()wjpnp5 +q. fgkm z9ofxght are dropped simultaneously from the same height. Ignore air resistance. Compare their g5iw p m pnq z)7x()jff+ok.9daccelerations.

  A brick and a feather fall to the ear 4ox0hi a(xq6 c4i.j9xoo-pxtth at their respective terminal velocities. Which object experiences the greater force of air fri4xxocaitj p xo4i0 x-q.h(o9 6ction?

  An object of mass m is hanging by a string from the ceiling of an elevat.5oy;cwarme 7 z p9k.vr q8ge8gc8)rhor. The elevator is moving up at constant speed. What is the te7)q g.5vcaw he ymzr8rco8r kpg;9 .e8nsion in the string?

  An object of mass m is hanging by a string))t iuaou8e0g20 hvi y from the ceiling of an elevator. The elevator is moving upward, but slowing dowu2 y )h8) eu0oitavig0n. What is the tension in the string?

  The force that keeps you from sld.sk,: r,nlnciding on an icy sidewalk is

  It's more difficult to start moving a heavy carton from resdf0w+tb1b z7 jt than it is to keep pw+bb1f7dtz 0 jushing it with constant velocity, because

  A horizontal force accnlv*zsbq,t / gj4e29qelerates a box from rest across a horizontal surface (friction is present) at a c, 24j ntbg9v/s zqqe*lonstant 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 ve*m5e8ec9wfzc locity. Thus we can d89mcwcze *e5 feduce that

  A block of mass M slides down a frictionless plane inclined at an angle q with t )gho3h06 vxmrhe horizontal. The normal reaction force exerted by the plane6 gh3) hmr0vxo on the block is

  A block of mass M slides down a z)n6bphl5t. yfrictionless plane inclined at an angle q with the horizontal. The normal reaction force exerted by the plane on the block is direct) t ln5zpb.h6yed

  A block of mass M slides down a frictionless plane inclined at angj9*tkow wkhsh9v 1p0 8w5 .svk30 bpe angle q with the horizontalwhv0wwpj b9p v. t*1skoge kh53 s09k8. The gravitational force is directed

  Two toy cars (16 kg and 2.0 kg) are released simultaneously on anlnnqvww8 4kp 5 hh1l70 inclined plane that makes an angle of 30e wit 50llhp8k h4w17qwv nnh the horizontal. Make a statement which best describes their acceleration after being released.

  An object sits on a frictf fjz+v :aw/l + znvi;qn+y*2j:gt;ftionless surface. A 16-N force is applied to the object, and it accel+*/t ilznawj; g 2y:f;n+v jf fzq:+tverates at $2.0 \; m/s^2$. 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 s. Wh*z1qk .mld(:l4bxj apat isx*lqp:d4m lkbja 1 z(. the average forward force on the car?

  Starting from rest, a 4.0-kg body reaches a speed of 8.mi- txmei:xa zb*9 5) d7zw1xm0 m/s in 2.0 s. What is the net force am9*m) :1z5z7wx ami xtd -bexicting on the body?

  An antitank weapon fires a 3.00-kg rocket w we d0-kowc6;9ljfhfk-bya5 1hich acquires a speed of 50.0 m/s after traveling1o0d y6c9f-5kj- f lwhe; bakw
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)ly imom f:yu/ef2i.hi3;hu / with the same force that you push a 10-kg mass from rest,um/2if o;uhyy/hli i. f me)3:

  What is the mass of a person who weighb8+9 dcf6.jp xlne (oswoh b72s 110 lb?

  What is the mass of an object that weighs 250 N on the sgy9-m qq2p 8vnurface of the Earth where the acce m928- gnypqqvleration due 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 obmr9f8b89,yyu 54 yniv 9z*fx t qkf3wiject on the surface of the Moon where the acceleration due to gravity is only 1xz5*mwtf39vry 8uy nq i, b9fki89fy 4/6 of that on the Earth?

  Object A weighs 40 N on Earth, and d5 hbd /btr360swm g7pobject B weighs 40 N on the Moon. The Moon's gravity is one sixth of Earth's. Compare the masses of the ob7twm3 d6dr/bs h0gp5b jects.

  Sue and Sean are having a tug-of-war by pulling on opposite ends of a 5.0-kg oxdd/3(d)amw rope. Sue pulls with a 15-N force. What is Sean's force if the rope m a( dd3dw/o)xaccelerates toward Sue at $2.0 \; m/s^2$?

  A stack of books rests on a level frictionless surface.ai+hday-b k*6af7 nm2 A force F acts on the stack, and it acy-6*fmib +7ah a2kndacelerates 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 schu y0tm+, +orjta roi5s 8w/7xki- *dmale in an elevator. What will the scale be reading when the elevatid8 h -o5*+,mwk o x/sr+t0at7iyru jmor is accelerating downward at $4.00 \; m/s^2$?

  A person on a scale rides in a.jhya* 5+gfbx 1eosy .n elevator. If the mass of the person is 60.0 kg and the elevator accelerates downward wit1xeb .yyhfgs*5. +joa h an acceleration of $4.90 \; m/s^2$, what is the reading on the scale?

  A person on a scale rides inubp jmqg-+22 d an elevator. If the mass of the person is 60.0 kg and the elev-+2j gpdb2mqu ator accelerates upward with an acceleration of $4.90 \; m/s^2$, what is the reading on the scale?

  Two horizontal forces act :jzb (qr4h8ayo1up0t on a 5.0-kg mass. One force has a magnitude of 8.0 N and is directed due north. The second force toward the east ha8ar4u bt z hqjp:(01oys a magnitude of 6.0 N. What is the acceleration of the mass?

  An object of mass 6000 kg rests on the flatbed f/ tb t.yt 4tx9hyjuxf1l; sk)*je62mof 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 n;t )xtt1sljutm . h yk 6fj4*/ef2yb9xot to slide forward into the cab?

  An object of mass 6000 kg rests on the flatb gi-w;j ;x5rxu 9aby*9etx-haed of a truck. It is held in place by metal brackets that can exert a maximum horizontal force of 9000 N. W eigx-* 9x;a;wuayb 9rt5j-xhhen 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 shown in Fig. 4-1, if M = 0.60 kg and m = 0.40 kgaq51cnt7ke qhe0: w1l, what is the magnitude of the acceleration of the5 0aq7w c: eqhnt1e1lk system? (Ignore friction and the mass of the pulley.)

  In the Atwood machine shown in Fig. 4-1, if M = 0.6. rhkald3az5)g31nm n0 kg and m = 0.40 kg, what is the tension in the string? (Ignore friction m.azga3rh1 l3dn5 )kn and the mass of the pulley.)

  A student pulls a box of books on a smurr8e f2 hjo iy.):;zgooth horizontal floor with a force of 100 N in a direiygr e z :jrho2f8;).uction 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 hosceol+qsmp*b s 7(,9plh2; lwrizontal 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, what is the nsop s;2ls,97elq(b c mhp* +wlormal force on the box?

  A traffic light of weight 100 N is supported brcrzuu;- m*5kf i-wx4y two ropes as shown in Fig. 4-2. What are the tensii;c- urf -*rxmk5wz u4ons in the ropes?

  In Fig. 4-2, if the tensions in the ropes are 50 N, what is the vil+uq(jl. h2rz-x*c mass of the traffizq.2 +(iujrx-hcl lv*c light?

  Two boxes of masses m and 2m are in contact with each other oyr 21pknr8p w;n a frictionless surfacery2ppkw r1 ;n8. (See Fig. 4-3.) What is the acceleration of the more massive box?

  Two boxes of masses m and zo5am 5:wmnx2zt + x.:+2msnjuom )z a2m are in contact with each other on a frictionless surface. (See Fig. 4-3.) What is the net fot+a:xm2o)zuznw amn o.5z 2jmm +5 s:xrce on the more massive box?

  Two boxes of masses m and 2m are connected by a rope. (Shuhe1p rh6 5x1ee Fig. 4-4.) If the forward force on the more massive box is F, what is the tension in the co h15p1ruh 6xehnnecting rope?

  Two boxes of masses m and 2m are connected by a rqnt) *uuu4 uz*ope. (See Fig. 4-4.) If the forward force on the more massive box is F, what is the acce*4z uu u)qut*nleration of the less massive box?

Two boxes are connected by a cord rrwoa x.rl4uje996a*9knl3 w,ln 7 qlnunning over a pulley as shown in Fig. 4-5. Box I of mas34nx7 ,6lr ola9jrla wnw euq9*kl .9ns
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 a deskv8m nlb;oe7 m5 are 0.40 and 0.30, respectively. What is the net force on the box when a 15 N horizontal force is applied to the;8o7 m mb5nlve box?

  The coefficients of snsfs ) pqt s(6;.zb7xntatic and kinetic frictions for plastic on wood are 0.50 and 0zs sx6p.)b ;tnfnsq( 7.40,
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 2a(n5afxt,b o*ze3c r level surface in the +x direction. It slows and comes to a stop with a con*x, an 5zac 23et(orfbstant 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 cnkn fg hy65,6a 5.0-N force. A 3.0-N friction force retards the motion. What is the accyc g6nnkfh56, eleration of the object?

  A horizontal force of 5.0 N accelerates a 4.0-kg mass, from rest, at a rate ofuk gug3kk. +-j $0.50 \; m/s^2$ in the positive direction. What friction force acts on the mass?

  During a hockey game, a puck is given an initial spu9snwv8lqy2, 08z x7 r6z wfeleed of 10 m/s. It slides 50 m on thewzr2ns z7v0wy8 elxq lf6,98 u ice before it stops. What is the coefficient of kinetic friction between the puck and the ice?

  During the investigation of a traffic accident, police2il+ t nyt2ti2 find skid marks 90.0 m long. They determine the coefficient o2+2ti2tt l nyif friction 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 m and 3m are stacked. (See Fig. 4-6.) The c 6ho:*z- -mi slqm1jlvf* )ktsurface between the more massive box and the horizontal surface is smooth and the surface between the boxes is rough. If th h*):czjmm lioqft -1k6v*-lse 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. 4-6.) Th3wkt7mj)xnf,ied0 13v hk x,le 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 coefficientjkm 1,k0,dx3fxh lvw)t e7 ni3 of static friction between the boxes?

  An object is on a frictionless inclined plane. The plane is ilmfnhnxfvd8:k22 x (r4; ty2gnclined at an angle 2gfn2xd: l(fkrt8 ;2m yn4hvxof $30^{\circ}$ with the horizontal. What is the object's acceleration?

  A 10-kg mass slides down a flat hill that (r9:xs10 5tvtfq ggocmakes 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 r(6 f, 1g0bso(aatrcqjx 3w4l 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;1 m0d2tpj. nxmkm,ypo2 c5cw plane 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 direct*tm0 mlpw/3gvly down an inclined plane, at a constant velocity of 6.0 m/s /gtwm0vlpm3 *.
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 ahfm5qtq7a7 b:;x)grrt1 akq * 5u: jcs 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 ,vu7eucqd87 1nkz0 ds slides down 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 alo c2)pp12nxgunwt-j7wq3b +.iess 1lmn m/ii-ng a rough surface. The cable attached to the log ma-17nns-b2p+mg )ns2 qiu em/13.cj xw iptwlikes 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 res (rn-hh t83oq et51tmvt on a rough inclined plane tilted at an angle oe35vhttrm18 ( tnh-oq f $33.5^{\circ}$ 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 ik qzdfnum0 -)vjc(nj- 043czdf :do*n nclined plane. The angle of incline is gradually increased until the object begins to slide. The angle at which this occ3d cfzon4n( j-c k d*:zqumj-n 0dv)f0urs is q. What is the coefficient of static friction between the object and the plane?