Which of Newton's laalguzuf* 9t(wg*y+ w3-r(5 emuf.cwzws best explains why motorists should buckle-up?

  When you sit on a chair, the resultiu:t:;*6vg kzgr7/ ti5v kr kaant force on you is

  In the absence of an external force, a moving object wi vbkd6tl) sd0e44)ugqll

  When the rocket engines-0blcd6z0f7v 7 *odog sygb6v on the starship NO-PAIN-NO-GAIN are suddenly turned off, while traveling in empty space, b07zdl0b*g vy76 sg v food-c6the starship will

  A rocket moves through empty space in a straig h5kslh/ jl/m b)u9-gaht line with constant speed. It is far from the gravitational effect of any star or planet. Under these conditions, thm 9k/)hu-5hg jl/sblae force that must be applied to the rocket in order to sustain its motion is

  You are standing in ap+rax7y w 8r-pt -2cbb moving bus, facing forward, and you suddenly fall forward. You can imply from this that the bu7b- yawc+8r-p bt p2xrs's

  You are standing in a uae-218 dpo/ 9bdipa wmoving bus, facing forward, and you suddenly fall forward as the bus comes to an immediate stop. What force caused 9b w2-d eoiaapd1p u8/you to fall forward?

  A constant net force acts on an object. Describe the6txw*hb sm4rtx;) /in motion of the object.

  The acceleration of an object is inversely propor 0qj ,nn*pizp0m:kda. 8na ews*;f+jstional to

  A net force F accelerates a mass m with an acceleration a. If thk b l1bdc39 0b2al-mvte same net force is applied to mass 2m, thebltbm3 bc-0da2 9k 1lvn the acceleration will be

  A net force F acts on a mass m kw 4pfcvwuq, 8a(rsi04szz-)and produces an acceleration a. What acceleration resu v,cfqw8)4sai(0w k4-rzp uzslts if a net force 2F acts on mass 4m?

  If you blow up a balloon, and then release it, the balloon will fn t 06ju(4pkmjy14dh xly away. This is an illustrationum4 d( 0xjjkntp1h4y6 of

  Two cars collide head-on. At every moment during the collisfpg*o4,vr3 cz ion, 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 first. This z vrgcfp*4 o,3is an example of

  If you exert a force 7-4r1*q67iqlq s a gqof uwjg2F on an object, the force which the object exerts on you wilq w74 iag 6oqqfgq1u2r j*7l-sl

  Action-reaction forc r7io0d1en vx7m:au;zes

  Action-reaction forcesvu 5xq7 u2uciadvv703 are

  A 20-ton truck collides with a 1500-dmy)a5a d1l 9clb car and causes a lot of damage to the car. Since a lot of damaga5a9clm d)dy 1e is done on the car

  An object of mass m sits on a flat table. The Earth pulls on this objeeco/o4ba (tj9ct with force mg, which we wi jo(oa4bt/c 9ell call the action force. What is the reaction force?

  A child's toy is suspended from the ceiling by means of a string. The Earth- i,vyk5uq56;d ulh yw pulls downward on the toy with its weight force of 8.0 N. If this is the "action force," what is the "rekv,d5 y5 ;uily hw-6uqaction force"?

  Your bat hits the ball pitched to you with a 1500pg- fx6+vzl6-7;y hhm agbfy*-N instantaneous force. The ball hits the bat with an instantaneous force, wh*f7gb- f - yzg66vpx+lhh;ay mose magnitude is

State Newton's three08(c z4tc.oqaqo3n j-iuaa3z laws.

  Mass and weight

  The acceleration due to gravity is lower on the Mrino2 ,lgpm76 oon than on Earth. Which of the following is true about the mass and weight of an astronaut on the Moon's su6rg2, n7moilp rface, compared to Earth?

  An example of a force which acts at ltd (n4j. ij5+d(zi*ai,s yrk a distance is

  Who has a greater wer)vh j 20hy zy-pvsx:y0a8rt( ight to mass ratio, a person weighing 400 N or a person weighing 60s vvtayr hx(p:)hz8y0 y2-0j r0 N?

  A stone is thrown straight up. At tnzh(hz x)2y3s, l1vidhe top of its path, the net force acting on ix1n 3l2)hysv(zi,d hzt is

  A 20-N weight and a 5.0-N weight are dropped simultaneo6.difzx;qwo d;9 uo 3ously from the same height. Ignore aiud;9zqo wo fd3ox6i ;.r resistance. Compare their accelerations.

  A brick and a feather fall to the earth at their respective terminal velocitie:wpj-g aeo-c gdg(x+(s. Which object experiences the gre(jx( c+do-wa-pe:g ggater force of air friction?

  An object of mass m is hanging by a string from the ceiling o: vydcvf .dvrtr+ i4 -)iuke7k 2l/-1g6ys dbof an elevator. The elevator is moving up at constant speed. What is the tension in thdr4/-v-uel2k)bgi.r cdk tvfv1 6 s o i+7:ydye string?

  An object of mass m is hanging by a string from the cei/+ s4j atbk*;5j) x:eg9y9 h rcnyqovngmv.)wling of an elevator. The elevator is moving upward, but slowing down. What is the tension in the ; n 4k wjx)v rjcbsntmoa 5*g9/ 9:.yy)vegq+hstring?

  The force that keeps you from sliding on an icy sidewal/aiq,sz0nb3rq- 9 ry pk is

  It's more difficult to s:f u29imojg 5mtart moving a heavy carton from rest than it is to keep push :ommju52fi9ging it with constant velocity, because

  A horizontal force accelerates a box from rest across a horizontal surl ueb(7m xyaff26onui l; nzd33).lb3face (friction is present) at a constant rate. The experiment is repeated, and all conditions remain the same with the exced aefibl3o3xuy)l2n b n( ml;u.6 37zfption that the horizontal force is doubled. What happens to the box's acceleration?

  A packing crate slides down an inclined ramp at constant velocity. w0j5n g f,w2oh(k wlm.Thus we can dem w2kl ,05(wfjghnw .oduce that

  A block of mass M slides down a frictionless plane inclined at an angle q wit pk ikp/8 gnn99et0po*f1xc2th the horizontal. The normal reapptn p2nkio/ge x*1 0k989 ftcction force exerted by the plane on the block is

  A block of mass M slides down a frictionless plane inclined at an an8 )u 9mpyqs/tmgle q with the horizontal. The normal reaction force exer9yut/m8)psmq ted by the plane on the block is directed

  A block of mass M slides down a frictimno*4n o /yyla3thk5.0 o tb*lonless plane inclined at an angle q with the horizo*0y/5y oh* tlb.nat om3 4onlkntal. The gravitational force is directed

  Two toy cars (16 kg and 2.0 kg) are released simultaneously on an in3y /, gx(hw evtjbq.ig 2bzp27clined plane that makes an angle of 30e with the horizontal. q, (27pjt g./vb3whzxy i2ebg Make a statement which best describes their acceleration after being released.

  An object sits on a frictionless surface. A 16-N fovrl3k,*uf30duo t (yxrce is applied to the object, and it 0x33d u y,rlfvuok*(t accelerates 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/,xr on63ooc9 zs in 7.0 s. What is the averageocn,xzo69 3 or forward force on the car?

  Starting from rest, a 4.0-kg body reaches a speed of 8) b29ns*feq(bmhqo b7 j(xiu(.0 m/s in 2.0 s. What is the nb bh i(bon*9s()j feqm 72(uqxet force acting on the body?

  An antitank weapon fires a 3.00-kg rocket which acquires a s(dziwwu l/0,k :zl*ykpeed of 50.0 m/s afterw (d wk:il,u*z0lzy/k 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 massv3r emb kc6pzg()ds,r 0u(-)e 9jksa g with the same force that you push a 10-kg mass from rest,z()r)sv(9r3e gab k6 0gd-e kmsu cpj,

  What is the mass of a person who weiga-kwoq2z prcbw zgu.i+m)1f *q rc4.0hs 110 lb?

  What is the mass of an obe; t))ztpm ys-ject that weighs 250 N on the surface of the Earth where tez- mt;pys) )the acceleration 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 object on t5aj)tovr6o+ q he surface of the Moon w6)+jqa orvt5ohere the acceleration due to gravity is only 1/6 of that on the Earth?

  Object A weighs 40 N on E w xj 0gy.1im,f bb3zvg-qj,(sarth, and object B weighs 40 N on the Moon. The Moon's gravity is one sixth of Earthwvy- f.j1gzq jb( ig,s3mx,b 0's. Compare the masses of the objects.

  Sue and Sean are having a tug-of-war by pulling eycidyeb866cfc7i6a n71 .wa on opposite ends of a 5.0-kg rope. Sue pulls with a 15-N force. What is S16 76ca.ay bi new eicf78c6dyean'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 s3 iu0 jemzw00f+gzi9 xtack, and it accelerates at +0z3wx0 igi0e9mjuz f$3.0 \; m/s^2$. 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 will7y s6 d8a7rl.e-h zvoh the scale be reading when the elevator is accelerating downwarrydsv6 -hloe7 8. 7zhad at $4.00 \; m/s^2$?

  A person on a scale rides in an elevator. ,rw91mr+ u, :olelorh lxv5(g If the mass of the person is 60.0 kg and the elevator accelerates dow vxlrgr, hou l1, m:(lre5+wo9nward with an acceleration of $4.90 \; m/s^2$, what is the reading on the scale?

  A person on a scale ri/afq-x+4yon.m zp mxoz e:y4(des in an elevator. If the mass of the person is 60.0 kg and the elevator accelerates upward with an -o4zon4.(mz:+x ay /qmx pfey acceleration of $4.90 \; m/s^2$, what is the reading on the scale?

  Two horizontal forces actgj h q)ayu/8 wjm4g7u( on a 5.0-kg mass. One force has a magnitude of 8.0 N and is directed due north. The second force toward thej ma j8u)y4/hgw7guq( 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 truck. It is held in place i-zh1a: ia+ suw-qzs/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 s1 qiszh:z-a-ui asw+/ topping distance if the load is not to slide forward into the cab?

  An object of mass 6000 kg rests on the flatbed of a t ku 6ye ,k9h2-qb6qn4*sk:6fz tutbzaruck. It is held in place bys t:6h-yu*kk,zaqtkfq4 966en z2bub 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 M = 0.60 kg am 6u: fh4tk 71;hnmvyhnd m = 0.40 kg, what is the magnitude of the acceleration of the system? (Ignore frictionthmnh41 vh fm:6k; 7yu and the mass of the pulley.)

  In the Atwood machine shown in Fig. 4-1, if M = 0.60 kg and m = 0.x y+)9isdt rq4,lwj: h40 kg, what is the tension in tlw:t qi 4rjdy hxs,9)+he string? (Ignore friction and the mass of the pulley.)

  A student pulls a box ofb m*ox9em))9cy,qmib gyl t5* books on a smooth horizontal floor with a force of 100 N in a direction)x e9*ity q mly)m* 9om5bgc,b 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 s4mv. hd+sxk: hj3n 3ukmooth horizontal floor with a force of 100 N in a direction of 37.0e above the horizontal. If the mass o vm3x3dh+j :4sh.kknuf 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 sup:k y1(g6pphd ,kumcx3ported by two ropes as shown in Fig. 4-2. What are the tension ,c(yk3 xgm:pdh1ukp 6s in the ropes?

  In Fig. 4-2, if the tensions in the ropes are 50 N, pn:ks n.26yhswhat is the mass of the traffic lights ky6sp2hn:n .?

  Two boxes of masses m and 2m are in contact with each other on a frictionless u 8 ,rr pmcnz+p08gwp 9x-zqs;)x3gwl surface. (See Fig. 4-3.) What8g z8 rwws, 0ng)pxz-pm c3x9;u rq+pl is the acceleration of the more massive box?

  Two boxes of masses m and 2m are in contact with each ucvs3qsh 7irk8;/wq* hal2 )hother on a frictionless surface. (See Fig. 4-3.) What is the net forrh7cl; qhav*/hi3us8)k 2q wsce on the more massive box?

  Two boxes of masses m and 2m are connected by a o zdg56h ,t:xq,jqc9hrope. (See Fig. 4-4.) If the forward force on the more massive box is F, what is the tension in the htxh,:,gq czo9 j d5q6connecting rope?

  Two boxes of masses m and 2m are connecsa7tua p87-ifted by a rope. (See Fig. 4-4.) If the forward force on the more massive box a-ai8t7 pfsu 7is F, what is the acceleration of the less massive box?

Two boxes are connected by a cord running over a pulley as shown in Fig. 4-8f(t1x(y ei *rmqzx7uqe 4 n)i5. Bt4n 7x imu *f(1(8xy)zer qeqiox 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 frictions between a 3.0-kg box anc*fe6pgalhs 3 *,cpr.d a desk are 0.40 and 0.30, respectively. What is the net force on the box when a 15 N *p rag.ceh36l,s*pcfhorizontal force is applied to the box?

  The coefficients of static and kinetic frictions for plastic on wood are 0uq7 ng e6 gn)8y.jiuxilxb 11+.50 and 0.y g)j81nub6elqx 7xiun+1 ig.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 ,r hd0rt9yv fv4 x.0ni 2vtht0+x direction. It slows and comes to a stop with a constant acce 9d0vhtn2rx v0y,4.vi hftt0rleration 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 hor 7bbr)a8toa ;jq; wm0eizontal surface is pulled by a 5.0-N force. A 3.0-N friction force retards the motion. What is the a oe braqbaj8w7t;0;)mcceleration of the object?

  A horizontal force of 5.0 N acce2ndwffj (bs7dpd 01/tlerates 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 puck is given an initial speed of 10 m/s. It slid+09eafdjm-td:v 5 ohdes 50 m on the ice before it stops. What is the coefficient of kinetic friction betwee f jade:md0- 5+oth9dvn the puck and the ice?

  During the investigation of a traffic accidml6ko+.x 9/8uwobqul ent, 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 prevailinqb+9 / luwku m6o8.oxlg 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.) Td. mw6m 3kou ipb6k3*v,mhur 0he surface between the more massive box and the horizontal surface is smooth and the surface between the boxes is rough.06 u ikrwh*vmdb3k3m. mup6,o 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. (See Fig. 4-6.) The surface :d+7d w zm), v)sqo+ duz+epfibetween 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 7zs)oq +pzdi:u md)++vdw,e fthe more massive box, what is the coefficient of static friction between the boxes?

  An object is on a frictiol d6n4 n4nvirqqjlec(3) e. hka jg3m07-wr:qnless inclined plane. The plane is inclined at an angle ofr q37v- n nh.q:ejerki3jnlq0mc4(6 wagl4)d $30^{\circ}$ with the horizontal. What is the object's acceleration?

  A 10-kg mass slides down a flat hill8/ ealk ,nr6*ghg2hemsm) (ju 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 smd*6nyp ql, ni:ooth 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 planekeq r07/m3*arnb p9btm j3. 0jpo+d mn 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 tt) / ijvfsp*2constant velocity of 6.0 m2j)/*spvft ti/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 roura+;:rerg .o-k hs.vw gh $37^{\circ}$ 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 apc8j6*phir dh)t h/3r 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 i.1zrpv5g zh0 500 N along a rough surface. The cable attached to the log makzi.g zr1v0h5 pes 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 rest on a iq4kc uzs,t+ 3rough inclined plane tilted at an anglek+siuq,4c3z t 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. Thew)vp1gn() kkb angle of incline is gradually increased until the object begins to slide. The angle at which this occurs is q. Wv(g w )p)1kbnkhat is the coefficient of static friction between the object and the plane?