Which of Newton's laws best expbsz868mb zxq 4ei 7t8ulains why motorists should buckle-up?

  When you sit on a chaefb5iq32uxk70-d+b3. x v-ejij bwd z w0hra6ir, the resultant force on you is

  In the absence of an external force, a mo0xi(a07x 6(vf hw) xn6ao asseving object will

  When the rocket engines on the starship NO-PAIN-NO-GAIN are suddenly ;qf1. ,qqcj1v vvzz+vn,7:ic r4ettqturned off, while traveltq7e1vr vfzq4 .;+: qvjvcq z itcn,,1ing in empty space, the starship will

  A rocket moves through empty space in a sk z jcd/c1+ 9,jxsw3dqtraight line with constant speed. It is far from the gravitational effect of any star or planet. Under these conditions, the force that must /3xz,+dcq9wsk jd c1jbe applied to the rocket in order to sustain its motion is

  You are standing in a moving bus, facing o; lhas xla**hmf.i :6forward, and you suddenly fall forward. You can imply from this that the buslli ax*oa :f.;6*m hhs's

  You are standing in a moving bus, facing forward, and you suddenl l9 tvlbf3.:zly fall forward as the bus comes to an immediate stop. What force caused you to ftf: 9 b3ll.lzvall forward?

  A constant net force acts on an object. Describe the motion of the objl.amb9 y; 45u e( tszmzced8n)ect.

  The acceleration of an objectec,7qpf p (s9h is inversely proportional to

  A net force F accelerates a mass m with an accelfi 6i3uo4 6 p+cb)ouvzeration a. If the same net force is applied to6vuib4c6 i+fzo3 u )po mass 2m, then the acceleration will be

  A net force F acts on a mass m and produces an acceleration a. What accelerai31fktp0 k8+dbsjs8 ttion results if a net 8kb80p3js1 +tsdftki force 2F acts on mass 4m?

  If you blow up a balloon, and ia/bw3;k eghhky +l 22then release it, the balloon will fly away. This isi gawby3/k2 ehhk+; 2l an illustration of

  Two cars collide head-on. At every moment during the collision bib+(bijt+ 1hv-1qq x, the magnitude of the force the first car exerts on the secon-+qhj (bvq1ti b+xbi1d 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 whia.cm4 z,xk(pzk.*n wm ch the object exerts on you will w ax k.*p,(kmcnzmz.4

  Action-reaction force 3ts1iqm f1/sxwximy+i3 3bd .s

  Action-reaction forces , jzpv3ol*wdb:7dmt tsk) 7h2are

  A 20-ton truck collides1y w/tqm .bg:k with a 1500-lb car and causes a lot of damage to the car. Since a lot of damage is doq:tyb/. mw 1gkne on the car

  An object of mass m sits on a flat table. The Earth pulls on thiskybmpv a2 * 5:zb6psj8 object with force mg, which we will call the action force. What is t k*5j6z pm a:2bps8ybvhe reaction force?

  A child's toy is suspended from the ceiling by means m2178imczz gjtra7(fz (ele;d0.u(kvfc km+of a string. The Earth pulls downward on the toyfd(m2e(ft(m ez7u clak 1jizz8rm+c.vkg7 0; 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 with a 1500-N iyr(01ejj p+34plu( hgiuo n0-rw2 y0w q a+ajanstantaneous force. The ball hits the bat with an instantaneous force, y0 eu 3phru0p-a 0g (l 1jinq(jy+ao+ wwaj2r4whose magnitude is

State Newton's three n4 i1vvd ) rgyh s(/a;+vb0epolaws.

  Mass and weight

  The acceleration due to gravity is lower j58 suv m0m9 wg*8c mce-a;snbon the Moon than on Earth. Which of the following is true about the mass and weight of an astronaut on the Moon's 9m-cc5m0wbuv8na;*js g es8m surface, compared to Earth?

  An example of a force which acts at a distan sv,f.-c(sgidt8d /jv , 7phvlce is

  Who has a greater weighm:/ue w8b86oe 8lo0p gs 0onghv+ du*qt to mass ratio, a person weighing 400 N or a person weighe0opb+g:w8/s nmqolg uv ehu 6 8d0*o8ing 600 N?

  A stone is thrown straight up. At the top of its path*k cij5d8y e(ke/ kw3u yx9)vr0nh v/l, the net force acting on e e9/ ckid )rv3yn/(h*wl5y8jvu0xkkit is

  A 20-N weight and a 5.0-N weight are dropped uwbwxb by 8.m.h78 2qosimultaneously from the same height. Ignore air resistancew8qx8m h 2byob..w bu7. Compare their accelerations.

  A brick and a feather fall to the earth at their respecaut; 7* 2:zwavk hnsta(--s7v4 euv vitive terminal velocities. Which object experiences the greater fou7ntv*va k-h;ia:t7 zsa 2(vs- u4ew vrce of air friction?

  An object of mass m is hanging by a string from the ceiling of an elevator. Th8*s b ;ntx rpauq0)3 tva*yo)ybc-w )ma9alq*e elevator is moving up at constant speed. What is*p03a -wyts)*v*) ;bu9oc 8yta)b anmlraqxq the tension in the string?

  An object of mass m is hanging by r3s lc 50:xjfba string from the ceiling of an elevator. The elevator is moving usr0jlb c 3x5:fpward, but slowing down. What is the tension in the string?

  The force that keeps you f opqs :-x/ gk7d*,esh/v -nevkrom sliding on an icy sidewalk is

  It's more difficult to start moving a heavy carton from rest than imvy3kr-(ay.7 q f5o6pr(w ksbt is to keep pushing5kr(-vwam6 skb(pyy .o37q fr it with constant velocity, because

  A horizontal force accelerate)5 8zw0 d b 23o4h3qstzi8ks6yqzdoha s a box from rest across 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 horizontal force is doubled. Wha k3h6d4z3qao)0 h5 2 o8q8ydziz swtbst happens to the box's acceleration?

  A packing crate slid*x4 . tiatyz2des down an inclined ramp at constant velocity. Thus we can 4ad2i*x tt.zydeduce that

  A block of mass M slides down a frictouykacxh/+*s*bj hh i:e 9-oks o:ss) o0o5)oionless plane inclined at an angle q with the horizontal. The normal reaction force exerted by to jkss+ 5o)9ebhuyk aoh:: )ssi-oo *c*/hox0he plane on the block is

  A block of mass M slides down a frictio6,wjd9up kifa.jm.h udr5;t9nless plane inclined at an angle q with the h t9f9hjad;. 5k.wrmuu,dipj6 orizontal. The normal reaction force exerted by the plane on the block is directed

  A block of mass M slides down a frictionless plm-b: g cnp5dy4 xoo) ui-f.m0nane inclined at an angle q with the horizontal. The gravitatio p:i 4m 5 -o-)nb.cxnmugof0ydnal force is directed

  Two toy cars (16 kg and 2.0 kg) are released simultaneoushtzt6ok;np 6ad; 7d;m )u :zhely on an inclined plane that makes an angle of 30e with the horizontal. Make a statement which best describes their acck : dd6)otz;t;uehn6a zp;m7h eleration after being released.

  An object sits on a frictionless surface. A 16-N force is applied to tafmqkv uj2 )vqzetb -1.z+.) zhe object, and it accelerate+tq .kfba 2)uzq1vv) mzj-.zes 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 m9 00fuu9hoqybykw8l6 * w-w5 xf(oukv/s in 7.0 s. What is twu9 k5hf6 l w8uo9 fv*x0y(oku0b-wyqhe average forward force on the car?

  Starting from rest, a 4.0-kg body reaches a speed of 8.0 m/s in 2.0 s. W m7iz4s nho(bd()nec: hat is the ned(en7 b:c hsi4nzm(o) t force acting on the body?

  An antitank weapon fires a 31q1boto1hzq l7sz h er8gk l.79 gls3).00-kg rocket which acquires a speed of 50.0 m/s after tr t1gq9.)81l7q zsoh solbg3z k1rhl7eaveling
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 5r y6hbef km5(same force that you push a 10-kg mass from refy( br k5h5me6st,

  What is the mass of a person who weighs 110 lb;ng:mzr;:jr 9pbenb9-r1 a +sgxmql 1?

  What is the mass of an object that weihi ld.w,r:( 5emtl*wz/fox : eghs 250 N on the surface of the Earth where the acoir:w,me .dl w/tfe5 z(*:xhlceleration due to gravity is $9.80 \; m/s^2$?

  An object has a mass of 60 kg on the Earth. What is the q oq 3/ :ku2rclh2o:nqmass of the object on the surface of the Moon where32/:nqq:o rl qcou2hk 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 4fjpx:q5 8 pb*4g9x tcy3kxde*0 N on the Moon. The Moon's gravity is one sixth of Earth's. Compare the masses ofx9pg k 4q p xtyjd*8x*c53:bef the objects.

  Sue and Sean are having a tug-of-war by pulling on opposite ends of ak;wzg ;9mdo s)c 9h.nm 5.0-kg rope. Sue pulls with a 15-N force. What is Sean's force if the ropezhd)ong c m.9ks9 w;;m accelerates toward Sue at $2.0 \; m/s^2$?

  A stack of books rests on a level frictionless surface. Ay8(d*c hyaaj( force F acts on the stack, and it accelej ya(* (8hdcyarates 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. Wz -6lpiqsi)n 3bj75mk l si,.vhat will the scale be reading when the elevator is acceleras36. il jvl5qz)n,i pimsk- b7ting downward at $4.00 \; m/s^2$?

  A person on a scale rides in an ewed/h a;n( af ha9*l1ps1 jbu6levator. If the mass of the person is 60.0 kg and the elevator accelerates dow nlaje;b(s/wh1da6u9h*a1 f pnward 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 the person is 60. pl6*tw k:3sdv xq*.fj0 kg and the elevator accelerates upward with tdxsjq*l 3w .6*k: fpvan acceleration of $4.90 \; m/s^2$, what is the reading on the scale?

  Two horizontal forcev9rb)0b n, zz889if+4 c,e rnucgagdys act 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 has a magnitude of 6.0 N. What is the 8dz cavbc0ifug9n ey9rr 4 +,ng8bz),acceleration of the mass?

  An object of mass 600 urieee: 0;bk( fw5eo)0 kg 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 distance if the load is not to slideufee(w)e; ibo 0ke5 r: forward into the cab?

  An object of mass 6000 kg rests onq: e zujug6e2) the flatbed of a truck. It is held in place zg6) equje:u2 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 to slide forward into the cab?

  In the Atwood machine shown in Fig. 4-1, if (upr0) eq 4;f p3sx ocnvur(8 on07jmpM = 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 pullepn0 s)rxp8r;(q3 v uejcpu fo0n4o(m 7y.)

  In the Atwood machine shown in Fig. 4-1, if M = 0.60 ks*1 o yp,va+yigw8 p:hg and m = 0.40 kg, what is the tension in the string? (Ignore friction and the mass of the pulley. +hi *,ws:o8 aypvpyg1)

  A student pulls a box fv+1 .x68*kd 9plol cedf5cmx of books on a smooth horizontal floor with a force of 100 N in a direction ol9+pffodv86. 5x* eccld1xkm f $37^{\circ}$ 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 /xrogae,7zvk y(. *ilwith a force of 100 N in a direction of 37.0e gvx* yo/,i(krl7a z.eabove 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 100 N is supported by two ropes as shown in2ll1fya6ec* z-o uvj*( e k3yf Fig. 4-2. Wljvfae 36( 1ekuz-y*yl f*2oc hat are the tensions in the ropes?

  In Fig. 4-2, if the tensions in the ropes are 50 N, what i4e tbg5t,r4upt5u )y us the mass of the traffic5)pt5u,b e4gur yutt4 light?

  Two boxes of masses m and 2m are in contact with each t o:exg5sv8 x8s5n8bi y -bcp4other on a frictionless surface. (See Fig. 4-3.) What is the acceleration of tc8xb :ysb xo-545 p8nei8vsgthe more massive box?

  Two boxes of masses mtu:ci-)jfg+sv zy+w : and 2m are in contact with each other on a frictionless surface. (See Fig. 4-3.) What is the net uft:j+s:gc vwy-iz+) force on the more massive box?

  Two boxes of masses m and 2m are connecfwj -uu.su* hl.o2i3waef x 92ted by a rope. (See Fig. 4-4.) If the forward force on the more massive box is F, what is the tension f wjwa.-u*h.2l o2suuf93ixein the connecting rope?

  Two boxes of masses m and 2m are connected by a *:is/u*rcpjn qa5x/rrope. (See Fig. 4-4.) If the forward force on the more massive box is *carp/nqu s:/ir* j5xF, what is the acceleration of the less massive box?

Two boxes are connected by a cord rurtce.bt-bws 3 bot1lbu sf;4b1vyu7n- .38ea nning over a pulley as shown in Fig. 4-5. Box Ibtbu -41vyebwbcs1n .3e8otubr7. l f3-tas ; of 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 frictions a8x 3zdjrws )mpkn h2lwg8s9f (w t02/between a 3.0-kg box and a desk are 0.40 and 0.30, respectively. What is the net force on the box whenp jhzd8mw9f)k2n x80r2 ws (glsa/3tw a 15 N horizontal force is applied to the box?

  The coefficients of static and kinetic frictionv c5h)jp5kk q la2ora) odv0tbp0k5*7s for plastic on wood are 0.50 and 0.40,*0 7vlok q)h5v 05tpbo ad25) pkajkcr
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 directi/ bi70rcm8lakiqyt-3on. It slows and comes to a stop with a constant acceleration o3c7 qm8lyr0t -/ kbaiif -$2.45 \; m/s^2$. What is the coefficient of kinetic friction between the object and the floor?

  A 10-kg box sitting on a horizontal surfac3+ml; zfsl3uxz1ce /+ ag)lo we is pulled by a 5.0-N force. A 3.0-N friction force retards the motion. What is the acceleration of tlofwlz mug;l za3 s/)ex++c31he object?

  A horizontal force of 5.0 N accelerates a 4.0-kg mass, from rest, at a rate of/4 v)pwj.zzvjuld4 y 4 $0.50 \; m/s^2$ in the positive direction. What friction force acts on the mass?

  During a hockey game, a pwfs e* 911x 9c*3(zjws4* hnhvxpeamduck 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 dj s94*svmp 3 eha(*n1efx w w*hxz9c1between the puck and the ice?

  During the investigation of a e i 3sw:asp41*c7, xli9/qtyzq f.fvrtraffic 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 9 sit,y3qex:r1 w/p4 v.qia f7scz*lfprevailing conditions. Estimate the speed of the car when the brakes were applied.

  Two boxes of masses m and 3m are stacked. (Sees3. aqi6eu6lx Fig. 4-6.) The surface between the more massive box and the horizontal surface is smooth and the surface between the i l 6.63aqsxueboxes 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. :- y4rjwuaj479qgtcq v -pws1 (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 is the coefficc1 r4q ujtwvjq-: 9ws- 4gyap7ient of static friction between the boxes?

  An object is on a frictionless inclined pla 3csg g3-j lcd9 pf*rbeec58n2ne. The plane is inclined at an angle o9dgce2epjl c5-8cr 3g 3nsb*ff $30^{\circ}$ with the horizontal. What is the object's acceleration?

  A 10-kg mass slides down a flat e8 ,bw4sfuf8 thill 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 plane with an anglz ynsr2 k5xb5r54uj* zx/n6nge 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 smwf0 :2m rmx5 -pabzkxxo*x-3sooth inclined 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 directly down an inclined pln3o(iz c:x/77pbzaex ane, at a constant velocity of 6o na/i(e7x p:3zbz7cx.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 rougia( ababzn:+u uo7l6 u;3 m9jf vv.9qlh $37^{\circ}$ inclined plane where the coefficient of kinetic friction is 0.20. What is the acceleration of the object?

  An object with a mas6u c wf:4j-qxjs m 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 along a rough surface.goq f:o-mf1 c* The cable attached to the log makes an -fco1 fqm*go: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 roup y/1r,n6ka kw 5bpbf9gh inclined plane tilted at an angle pbnb, 65/ra9y fwp1kk 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 inclined plane. The angle of incline is graij)m,l bj.+-dq 5,(wumb jzwjdually increased until the object begins to slide. The angle at which this occurs is q. What is the coefficient of static ,zu j+j md.bw5liq)(-jm,jwbfriction between the object and the plane?