Which of Newton's laws best exp s+9 5leu7asqz( (; rzn;2x0cifb dmqblains why motorists should buckle-up?

  When you sit on a chair, t)hma pfk6z j5/op,dx)tv u40 xhe resultant force on you is

  In the absence of an external force, a mo88ur23(s9 ecfgah b jhving object will

  When the rocket engines on the starship NO-PAIN-NO-GAIN are sk r3p7 )w8xdvsuddenly turned off, while traveling in empty space, the starship w3 7p8)dr vskwxill

  A rocket moves through empty space in a straight line with constant speed. Itv a)0x2(fh cdd is far from the gravitational effect of any star or pla x2fc()hdv d0anet. Under these conditions, the force that must be applied to the rocket in order to sustain its motion is

  You are standing in a movf0 wg*e2z5go fing bus, facing forward, and you suddenly fall forward. You can imply from this that the2 0gfz *g5wofe bus's

  You are standing in a moving bus, facing forward, and you sudde;o0 azpdb n 5xwq/an(2h4 kbj4nly fall forward as the bus comes to an immediate stop. What force oqnbhj/p0kw xbdnaz 2a; 4(54 caused you to fall forward?

  A constant net force acts o 0-0sab7gaejiz .,vvfe7s/xun an object. Describe the motion of the object.

  The acceleration of an object is inversely proportionalcdmxo tb6j3ujk9k +)o 5ip f.wl. r-/a to

  A net force F accelerates a mass m with an afe2yn4uf q;(ph- p (vhcceleration a. If the same net force is applied to mass 2m, then the acceleration willyph fhu(-2p;4 fvqn( e be

  A net force F acts on a mass m and produces an acceleration a. u7vw4s ki /yff54ef0sbyztd1 *gtrha;9 6 i0pWhat acceleration results if a net ffvy57 t 9de6p41grbf;k/wsia 0t*4huy0zfi sorce 2F acts on mass 4m?

  If you blow up a balloon, as4 pxp23p czhu9f kpf8,w:z s6nd then release it, the balloon will fly away. This is an illustration c:u 4wsp,khps 2x3zp98fpzf6 of

  Two cars collide head-on. At every moment during the collision, the magnitudi(j/.q r5kbpa+ot7)l qlu0uw 5q 2 oeje of the force the fi qiop7klw.q u/bjje l+(r 5qau2t) o05rst 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 object1s km*l e jnvbi4s.2s: xod7md7 8pcx), the force which the object exerts on you will*d8ocj es ksmx b)2p7m 7.lxv1idns4:

  Action-reaction forc; 8.r vnczgxw6za5o kai9y*z8es

  Action-reaction forces aregn/9:grld 0k w

  A 20-ton truck collides with a 1500-lb car and c-d 1zpfw(nigamevgm-,nt qp9+b s52 ; auses a lot of damage to the car. Since a lot of damage isg-+v t ;enqiz19ap2sm ,-f5w mg nbp(d done on the car

  An object of mass m sits on a flat table. The Earth pulls on this object: asmc.b (s1hxjyk68e with force mg, which we will call the actmcsxk(6bhj8s y: e.1aion force. What is the reaction force?

  A child's toy is suspended from the ceiling by means of a stwdq2zcc4eo14*k *ycynh7 t8 t ring. The Earth pulls downward on the toy with its weight force of 8.0 N.c4q2dt4 o n ckhe t8czw17*yy* If this is the "action force," what is the "reaction force"?

  Your bat hits the ball pitched to you with a 1500zoq+b g9/g**opt +dxt -N instantaneous force. The ball hits the bat with an instantaneous force, whose m /ogo *x 9qbtd+g*p+ztagnitude is

State Newton's three laas /):v cm(zjuws.

  Mass and weight

  The acceleration due to gravity is lower on the Moon than on g izo+p4w*n) nEarth. Which of the following is t*nop )4g+wzi nrue about the mass and weight of an astronaut on the Moon's surface, compared to Earth?

  An example of a force which actsf8(o bjex39k izkth jqxd:;40 at a distance is

  Who has a greater weight to mass ratio, a person weighing 400 N or a person weer pj0;h7:pc wy(g,wv 8,0ufmwbdeo;igh08dp;jyc powbu e7,vrf (wmg:h ew0;, ing 600 N?

  A stone is thrown straight up. At the top of its path, the y :h5g)vay4tdu3q 7zmnet force acting on it is ) 73qa4gum y:vht5yzd

  A 20-N weight and a 5.0-N weight are droppedfx/+27-*)z 9plz mt aas+rarm -oeiez simultaneously from the same height. Ignore air resistance. Compare their accelt +e-2 lmzs) axmp -9zifa+rre/*a7 ozerations.

  A brick and a feather fall to the earth at their respectiv:v2xau(d4b yt n*fu lfi9+l+t e terminal velocities. Which object ex2f ttnf: 9di uly4u*lb va+(x+periences the greater force of air friction?

  An object of mass m is hanging by a st bt94l+)7rmh eszz hi-ring from the ceiling of an elevator. The e zhbm- 7re4 +zist9l)hlevator 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 efkwhi b4wh:jq 8 h;5ww-f bz92i0gc1of an elevator. The elevator is moving upward, but slowing down. What is the t8 q;h04kb cfj1g iwhwww b f25hiz-:e9ension in the string?

  The force that keeps you from spz/l 6avh46p ; 5rawmjliding on an icy sidewalk is

  It's more difficult to start moving a(mfql i95)0rk t5siul heavy carton from rest than it is to keep pushi 9sl (m5 fi)5ktilqr0ung it with constant velocity, because

  A horizontal force accelerates a box from rest acros03 8jk 4yg3 zabm8ummzs 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. Wb0zm3 u8my3mkzgj8 a 4hat happens to the box's acceleration?

  A packing crate slides down an inclined rampb58bl6ct(f mx at constant velocity. Thus we can deduce thatbtx c(6mb 8f5l

  A block of mass M slides down a frictionless plane inclined at an angle qq 7 b z4uab,s-7me:yzn with the horizontal. The normal reaction force exerted by bbne :m-qs,77 z z4uyathe plane on the block is

  A block of mass M slides down a frictionless plane inclined atjx 5vc0/ne1lm an angle q with the horizontal. The normal reaction force el v0cx 1/nemj5xerted by the plane on the block is directed

  A block of mass M slides down kr50b 2h7kiye7p / kup67ottta frictionless plane inclined at an angle q with the horizontal. The gravitational force is d ptut 577kry7o6/itk k 2bep0hirected

  Two toy cars (16 kg and 2.0 kg) are released simultaneously on an i 9gh3b87 emhh9u*xw1fs v;p0ca g+e0n afex u9nclined plane that makes an angle of 30e 03 xv1u+9hf70fe h amhue w ngpa99gsce8bx ;*with the horizontal. Make a statement which best describes their acceleration after being released.

  An object sits on a frictionless surface. A 16-N f c4e16g/jlxpf+8zzy*l etaik r(8 ) kiorce is applied to the object, and it accelerates at6)cxpz/zlry8eelkg+i1i*8 k (jt4a f $2.0 \; m/s^2$. What is the mass of the object?

  A sports car of mass 1000 kg can accelerate from rest83, exnep h)kzkck wus61n5hl)k ;n0s to 27 m/s in 7.0 s. What is the average forwak c)68 hk3nu 1k0nw;lznep k),hx5 essrd force on the car?

  Starting from rest, a 4.0-kg body reaches a speed of 8.0 m/s in 2.0 s. g2 /y4meuac.b What is the2emcyg4b./ au net force acting on the body?

  An antitank weapon fires a 3.00-kg rocket which acquires a speed of 50.0 m7w9;g tlncxilcx / 3e1/s after 7wc cn39x llxet;1g/i 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-ii46uxh.ctz67*c k di kg mass from re x*7zt 6hc6duk4i ii.cst,

  What is the mass of a person who weigh y9junlbvefp nfkk; k -*(obsf0/10f4s 110 lb?

  What is the mass of an object that weighs 250 N on the suckj9b;k -6 fthrface of the Earth where the acceleration due to gr 9 tk;fcbj-6khavity is $9.80 \; m/s^2$?

  An object has a mass of 60 kg on the Ea x7w5f8g an kd;i78qzvrth. What is the mass of the object on the surface of the Moon where the acceleration due to gravidf8zaix ;7qn vk5 87gwty is only 1/6 of that on the Earth?

  Object A weighs 40 N on Earth5hfhx b,w.xk0jgd zcx (7,* zx, and object B weighs 40 N on the Moon. The Moon's gravity is one sixth *zdjbh,75xk0xgc,z. xxwh f (of Earth's. Compare the masses of the objects.

  Sue and Sean are having a tug-of-war by pv6 l,- s2spvinn vkz43ulling on opposite ends of a 5.0-kg rope. Sue pulls with a 15-N forcvi2sz- kn,4lvn3vs 6pe. What is Sean's force if the rope accelerates toward Sue at $2.0 \; m/s^2$?

  A stack of books rests on a leve6akcx2xsl-usu2 q37 el frictionless surface. A force F acts on the stack, anduqx23-e7s2s kaxucl6 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 scale34 2g 30rigyki-i- zfklb3sd b in an elevator. What will the scale be reading when the elevator is accelerating downkf- br33g i2k0id34 bisgzyl -ward at $4.00 \; m/s^2$?

  A person on a scale rides in an elevator. If the mass of the pers0+y: du p fqf1vhwim38on is 60.0 kg and the elevator accelerates downward withv8h+i f qwp my31d:f0u 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 persoh4uq/8atvi v.z -q- myn is 60.0 kg and the elevator accelerat- yq8vq-.i/ 4vumzth aes 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 has k21kzgi ;thc9a magnitude of 8.0 N and is directed due north. The second forceh1g zt c;ki92k 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 gwvo7du4v/6 n 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 slide forward iu gvno v7/d46wnto the cab?

  An object of mass 6000 kg rests on the flatbed of a truck. vn/3 9g5 u2epgto tbr:It is held in place by metal brackets that can exert a maximum horizontal force of 9000 Ng/: png bo2t3v59etur . 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 M = 0.60 kg and f2 e8 ;pkw7qbqm = 0.40 kg, what is the magnitupq2k f e;87wbqde of the acceleration of the system? (Ignore friction and the mass of the pulley.)

  In the Atwood machine shown iq*ep 0l:vt4r9a ar +c)h u,ovvkxz9j)n Fig. 4-1, if M = 0.60 kg and m = 0.40 kg, what is the tension in the string? (Ignore friction and the mass of thava): xcqlt9e+,jz vp)r4hr* 0u9 vo ke pulley.)

  A student pulls a box of books on a1aypoa.f, 0vu smooth horizontal floor with a force of 100 N in a dirv fya.op ,u1a0ection 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 of 12wc:teb-z54xhivwq v9h dm :800 N in a direction wez :tmv5hc:w b2vi4d8 9x q-hof 37.0e above 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 supp4/lgw djq5o )aorted by two ropes as shown in Fig. 4-2. What are the tensions in the o)qg5adwj 4/ lropes?

  In Fig. 4-2, if the tensions in the ropes are 50 N, fd; ws5f/vt a 0q;c5hdwhat is the mass of the traffic l5;/afdt d 5c0vq;wh sfight?

  Two boxes of masses m and 2m are in contact with each other o+82kgej(6 /ij jkrdpyn a frictionless surface. (See Fig. 4-3.) What is the acceleration of the more massive box?i8/( yj kjj6rgpd+2ke

  Two boxes of masses m and 2m are in contact with e*xif faz ;/gagmdm(yoa l28u36 qx*c 6ach other on a frictionless surface. (S6xx goc * a*2lfyqzgdm8a6ifa;(/m 3uee Fig. 4-3.) What 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 t(6uttc *h g( +xmz.owjhe forward force on thezmu(tto*+( . gjhcw x6 more massive box is F, what is the tension in the connecting rope?

  Two boxes of masses m and 2m are connected by a rope. (See Fig. 4-42 /9.rymy qxdrd7p3ys.) If the forward force on the more massive box is F, what is the accelerati7dryy29x rs.q/m3dy p on of the less massive box?

Two boxes are connected by a cord running o(2y klrij*x 9.npkzsyt7 5x ee5*m5zj ver a pulley as shown in Fig. 4-5. Boxiz nskjr7x* j55y9p2x ly*ze(ektm5 . I 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 fri1o/,o2fz i: wm1xen psz9 jaq+ctions 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 applied to qo/ : xoz,ms1i1+z2a wfnp9ejthe box?

  The coefficients of static and kinetic frictions for plast)k 3sso-n7la 5ykmyya(0y7/rg+p z t ric on wood are 0.50 and 0.40,)yn/3s k+ayy(t- 7k lar5yogmp7s0zr
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 comes to+ 0gyp8*b8h ipro2 mih a +hbriyp*imo08 2 8p ghstop with 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 horizontal surface is pulled by a 5.0-N force. A 4dfe2,j orzcpbp k-/-3.0-N friction force re r24 k,ejd fz-o/bp-pctards the motion. What is the acceleration of the object?

  A horizontal force of 5.0 N accele5hvtgkqb*n /:rates 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 pa14o0pcel; ie uck 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 between the puc 14eai0l;pceo k and the ice?

  During the investigation of a traffic accident, police find ski1 ;+uj qfpb,sxd marks 90.0 m long. They determine the coefficient of friction betwe+,b f;1spqux jen 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 sd4l 4qlmemd3 6urface between the more massive box and the horizontal s qdl m63dm44elurface 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 e*qx7y km/2q rc42wh aand 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 rougy c2xrawq 74 q*2ekh/mh. 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 plamhalnvi l3n7+g 7 5)xrne. The plane is inclined at an angle o3hil5n ga7x ) +lrmv7nf $30^{\circ}$ with the horizontal. What is the object's acceleration?

  A 10-kg mass slides down a flat hill that makes an angle of gpm9h(22vrje $10^{\circ}$ with the horizontal. If friction is negligible, what is the resultant force on the sled?

  A mass is placed on a smooth ilx1zy :hlp 79zwc mzo- ,rt78ynclined 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 y/pruqqkdyi9)(f 3pl( 36e2bnqr -h zinclined 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 plane, at a consta (kv w9qh+gn 89i3xzrynt velocity of 6.0 r9n38khxzwyvq +ig 9(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 doz-af6 x-s7:ug4bk p)vu u2okmf2q:b swn 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 a 3316p(tg c- jmjflheorough $37^{\circ}$ 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 surfacepv ; cao,1b/s(zb x3ep. The cable attached to the log makes an ang;ppv3(sx1obce,/z able 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 froma nlw)dsula/1 gj r 8 waeby25371r1sd rest on a rough inclined plane tilted at an angle of /g ls15 ljydadsr71rwna ua8ebw1)23 $33.5^{\circ}$ 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. Thepcrac3 7)qi p; angle of incline is gradually increased until the object begins to slide. The angle at which this occurs i7 pc)irqa3 p;cs q. What is the coefficient of static friction between the object and the plane?