Which of Newton's laws best explains why motorists should h 0)yg awnhg4,buckle-up?

  When you sit on a chair, the resultant force on you iszx 8czem1qy *lgc796n

  In the absence of an external force, a moving obj3eq 24c 0 ,ni1xrzjvfject will

  When the rocket engines on the starship NO-PAIN-NO-GAIN are suddenly turned ovack/rl;h)v9 1 ba7ykff, while traveling in empty space,9yb);avv7a kh/ krcl 1 the starship will

  A rocket moves through empty space in a straight line with *4gao 7 joac06 qxvt:kconstant speed. It is far from 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 motiovg0a :c kq*o6x aj7to4n is

  You are standing in a moving bus, facing forward, and y6vx h fr8k2r0ihdu5-.d e lo0wou suddenly fall forward. You can imr-u6wfdh d0i5hvoxrke 28l. 0ply from this that the bus's

  You are standing in a moving bicpuz1n)s5fyf h3x)0us, facing forward, and you suddenly fall forward as the bus coms0 )1ui)hf n3zy5pfxces to an immediate stop. What force caused you to fall forward?

  A constant net force acts wyk ef.ba,3h2:o5va v -/sz-g;b gzsa on an object. Describe the motion of the object.

  The acceleration of an object is inversek1c p)r,xh*cdly proportional to

  A net force F accelerates a mass m with an acceleration a. If the same net forwvlg5h 9wi *b7v/app5k 3fr(g5(bsoz ce is applied to mass 2m, then the acceleratib(kz* p3ov7 55(gif 9pawbrv/hsw gl5on will be

  A net force F acts on a mass m and produces an acceleration abpzty2g aa: l 3v(x06m. What acceleration m:p v6 azb0a3 (xgt2lyresults if a net force 2F acts on mass 4m?

  If you blow up a balloon, and th0 oe7:t6skx+zs xtmp 8en release it, the balloon will fly away. This is an ilx o 6sz8 pt0t7es+kmx:lustration of

  Two cars collide head-on. At )r c0lg vl;me:l )-jfnevery moment 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 exme)0 ;:- vfjll ln)rgcerts on the first. This is an example of

  If you exert a force F on an object, o vhn +yx04ypywyv/a2x*6x o17-awsqthe force which the object exerts on you wil+apy qyws1nxvy42xay *7v/x -0o6 ohwl

  Action-reaction force un (.i-wi -:)i*vqp 1zazbdtrs

  Action-reaction forcal++fxo-t-++3ibxoa g w ltvgg*5 c*ues are

  A 20-ton truck collides with a 1y9t- 8fj4f4:snweial 500-lb car and causes a lot of damage to the car. Since a lo4:ilfynaes-t w84f9jt of damage is done on the car

  An object of mass m sits on a flat table. The Easa0jf vp3;yyl6 q za-8rth pulls on this object with for3 -yy0fa;8 6zvljqaspce mg, which we will call the action force. What is the reaction force?

  A child's toy is suspended from the ceiling by means of a string. The bchn8 k- l(v ag6bm7x6sm9,yy Earth pulls downward on the toy with its weight force of 8.0 N. If this is the "action force," what is the "reaction forylm cbk9x87(h ng, -v aysm66bce"?

  Your bat hits the bar rlenhumcz( )195ns5*ri/ o xll pitched to you with a 1500-N instantaneous force. The ball hits the bat with an inst*5ren)sm c51 (orr u9inzxhl/antaneous force, whose magnitude is

State Newton's three lawse;y8:mr9-fsald g2ntyk1 3zf .

  Mass and weight

  The acceleration due to gravity is lower on the Moon than on Earth. Whicfwi8h/+, l9u uw 7uprrh of the following is true about the mass and weight of an astronaut on the Moon's surface, comparef7uu ,+wr huw i9/pr8ld to Earth?

  An example of a force which acts at a d31gse+np jcih618gj distance is

  Who has a greater weohtn9yd+ o i;g:nwq.4 ight to mass ratio, a person weighing 400 N or a person weighing 64h+:q;no nyw.i t d9og00 N?

  A stone is thrown straight up. At the top of its path, the net fo :k3hkgw 2iej7rce acting on it isjw ihke23kg: 7

  A 20-N weight and a 5.0-N weight are dropped simultaneously from the same heights) w*7d(pf2b luas/je . Ignore w/b7sf2) l(ajesup d*air resistance. Compare their accelerations.

  A brick and a feather fall to theq3jv qw2* at,5iter2 t earth at their respective terminal velocities. Which object experiej2q ir tt5 a3w,2qet*vnces the greater force of air friction?

  An object of mass m is hanging, bbzk4 j3ms.n by a string from the ceiling of an elevator. The elevator is moving up at constantk. b,4nzjs3b m speed. What is the tension in the string?

  An object of mass m is hanging by a string from the ceiling of an elevam erzk52ms 1 xg,js)p7-la ,bxtor. The elevato2 gx m,1), m5s-sbe lpjka7zxrr is moving upward, but slowing down. What is the tension in the string?

  The force that keeps you frokft-cm f0r o 5nr6 19r3buisd)m sliding on an icy sidewalk is

  It's more difficult to start moving a heavy carton from rest than it jbky,c- zt/5x1cg. fe is to keep pushing it witcygc.5 ef1,k btx/jz-h constant velocity, because

  A horizontal force accelerates a box from rest across 1o0 ztss*kr 1da horizontal surface (friction is present) at a constant rate. The expr0o11tss z kd*eriment 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 constantvtkg6y9duar k l8* .uy.n v;n7 velocity. Thus we can deduce thu t.*9k8dykng7vunlv6ra . y;at

  A block of mass M slides down a frictionless plane inclinedo i9pu4mqs2a1oz o7 1d at an angle q with the horizontal. The no4pq2oz9i1o 7m 1ousadrmal reaction force exerted by the plane on the block is

  A block of mass M slides down a frictionless plane inclined at an angle q wi3 s)y1h7hv+3 xjwxii60qyfwac;u qm-th the horizontal. The normal reaction force exerted by the plane on the block is dirw)u03ci-q qmhy 1fva;h+ 6ij ysx3x7wected

  A block of mass M slides down a frictionless plane inclinedwo,ckt+4 fw/sj*dxzl2 x 6f+ *yjfv0e at an angle q with the horizontal. The gravitational force is d2f0 sk ,wv*zj4cyxjt x*df+ +6le ofw/irected

  Two toy cars (16 kg and 2.0 k: sqptx :3mqz.g) are released simultaneously on an inclined plane :sq:3z.tx q pmthat makes an angle of 30e with the horizontal. Make a statement which best describes their acceleration after being released.

  An object sits on a frictionless surface. A 16-N force is /v1d sne t88pnyw))exapplied to the object, and it accele18yp/)dexvwn n8es ) trates 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. d +3; jywno;a ,qbfo*ogdc f-0; gfhi6What h-co ,oga fjyi;0 fnq6bdg ;dw3* ;of+is the average forward force on the car?

  Starting from rest, a 4.0-kg body reachesy;cjpqx5 /+qp k*bv4m a speed of 8.0 m/s in 2.0 s. What is th; *q5cv/+p qbxmy k4jpe net force acting on the body?

  An antitank weapon fires a 3.00-kg rocket which acquires a speee( )ya f2zw/ynk9 fk3b0et+ugd of 50.0 m/s after trz)9 (kwgna0+3bk/y2uf tey efaveling
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 m+5aqeck yk xb6y;gg7 0ass with the same force that you push a 10-kg mass from rest,gy kyex7bkg + a05qc;6

  What is the mass of aavse e 4kg 62:/usoeoq0jdz 75 person who weighs 110 lb?

  What is the mass of an object that weighs 250 N on the surface of the Earth kk a 5wqz34r2kwhere the acceleration due tqk a 54zw2k3rko gravity is $9.80 \; m/s^2$?

  An object has a mass of 60 kg ongac4t 0f- m*aj the Earth. What is the mass of the object on the surface of the Moon wa m*-0tg 4jafchere 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 40 N on the Moon. The Moon' 6y8n*ihx/ 7hisz( phks gravity is one sixth of Earthzn(yi6 /i8* 7k hhhsxp's. Compare the masses of the objects.

  Sue and Sean are having a tug-of-war by pulling on opposite ends of a 5.0bcd 2/rqk q v)w3vu*is3, u,zq-kg rope. Sue pulls with a 15-N force. What is Sean's force su,qw23r,d ki/q )b*vc uvqz3if the rope accelerates toward Sue at $2.0 \; m/s^2$?

  A stack of books rests on a level frictionless surface.y yks*.3qww: wcg/a j- A force F acts on the stack, and it accele .gqk:*wcwys-3y /wajrates 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 ahllv szo5hvrc69i570mc3nc9 scale in an elevator. What will the scale be reading when the elevator is 9cn57h0o3 6hc5 irvlslcm 9 vzaccelerating downward at $4.00 \; m/s^2$?

  A person on a scale rides in an elevator. If the md nv ,*z;l.chd 1dxk/1c zk;lajbz3*m ass of the person is 60.0 kg and the elevator accelerates downward with an accelerationc**/k 1,3xnlc dzvlbh dk.;djz1;maz of $4.90 \; m/s^2$, what is the reading on the scale?

  A person on a scale rides in an elevatoxwfbn m4q;gzu br/s5*ekt0+ *r. If the mass of the person is 60.0 kg and the elevator accelerates upward wit*b+u gn 0x;bqtkwe*rsz4m 5f /h 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 forhyl-hg)zidd) 8e/w sc*e-p e7ce has a magnitude of 8.0 N and is directed due north. The second force toward the east-)wezl e-y/ ieh8)gc ddsp7h * has a magnitude of 6.0 N. What is the acceleration of the mass?

  An object of mass 6000 kg rhx *t/lks c.f.ests 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 ksf*/h ct.lx .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 kg rests on the flatbed of a tr:s3c xdb +ue,/cnpqa(rc9z8 )pdm :hm uck. It is held in place by metal brackets that can exert a maximum horizontal/re (dcm )uc sp:+ndxbzq,:c a38 phm9 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 and m = 0.40 kg, wha ph8kq3v64ss .x*;bnangwm 4 ht is the magnitude of the acceleration of the system? (Ignore friction and the mass of the pulley.)36q; mspn*.g4 4 awb hxhvsn8k

  In the Atwood machine shown in Fig. 4-1, if M t b41sisvik -91 v.8gkx jim9m= 0.60 kg and m = 0.40 kg, what is the tension in the st9s41 m-kv8x9itbigv ji.smk1 ring? (Ignore friction and the mass of the pulley.)

  A student pulls a box of books on a smooth horizontal oey/gz4r c: pk/ed,cp2e+.wgfloor with a force of 100 N in a direcr,docc/pze 4p.w gyk2:+eeg / tion 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 foz 8xiet(8crd3 9foh t-rce of 100 N in a direction of 37.0e above the horizontal. If the mass of the box and thihttx f-3 ( rz9ced88oe books is 40.0 kg, what is the normal force on the box?

  A traffic light of weight 100 N is supported by two rop:7-ordbkap 2ves as shown in Fig. 4-2. What are t7ovak-rb : dp2he tensions in the ropes?

  In Fig. 4-2, if the tensions in the ropes are 50 N, what is the mass of thjb 9 71f vwj2( 92mypmz)mgyhve traffimj2bh9(my7z fy1)2vjg wpv9m c light?

  Two boxes of masses m and 2m are in l38yy6)c tk bgov87wncontact with each other on a frictionless surface. (See Fig. 4-3.) What is the acceleration of the more massive )3oc7nvb8 6wyy klt8 gbox?

  Two boxes of masses m and 2m are in contact with each other on a frictiothc)6 qf a,z1cxj,l9 tnless surface. (See Fig. 4-3.) What is the net force on the ) atqc,txhj f61czl9, more massive box?

  Two boxes of masses m and 2m are connected by a rope. (u)d;l79 em5cmx8 cnaySee Fig. 4-4.) If the forward force on the more massive box is F, what is the t7)u x9md yea5nl cc;8mension in the connecting rope?

  Two boxes of masses m and 2m are connected by a rope. (See fjmpr/39(r6le e*zt o tuzn)4Fig. 4-4.) If the forward force on the more massive box is F, what is the ( 9uom6lt f rz 4z3teen)*p/rjacceleration of the less massive box?

Two boxes are connected by a yqp b9r+qa;ssr+(gj5 c we8h8cord running over a pulley as shown in Fig. 4-5. Box I9h +ssr+ ye;8g crqqj( b5wpa8 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 betlva sr 0p9*kq k9b63zpween 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 the bo pbls3paq9 v*9kr6k0zx?

  The coefficients of static and kinetic frictions for plastic on wood are 0.50 ad t5pd1xn.d7q* gc:(8 mdzvl tndl .(dd7v1 8dznmdp qg*cx5t:t 0.40,
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;pj69trr4xlr;l;wnau-jg/ g in the +x direction. It slows and comes to a stop with agxnul j69wj- t;;4;r prar/lg 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 fo*5 ox0-8ip6ynlamh ) lvzcsu,rce. A 3.0-N friction force retards the motion. What is the accvy50 lsnlp-,x m68ao* chzi)ueleration of the object?

  A horizontal force of 5.0 N acceleratesdgv 2l dmy57,a+2jpvj 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.6witjj:et) k1 It slides 50 m on the ice before it stops. What is the coefficient of kinetic frj teitw: jk)16iction between the puck and the ice?

  During the investigation of a traffic accident, police find skid mar*kg- z-tfo/:h py(7tdpk exl;ks 90.0 m long. They detko*hyp e/7;pdlkttxf -g:-(z ermine the coefficient of 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 surface be0ly9 w3, pcdkfl 7ha;ytween 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 h pwy9lkcd,7;yl 0a3fmore massive box, what is the static friction force on the less massive box?

  Two boxes of masses m anj dw/(r + 5)8ovmqpesxd 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 rough. If the less massive box does not slide on the more massive box, what is the coefficient of static friction between to/ sqd)r(+5 p vmjxw8ehe boxes?

  An object is on a frictionless inclined plane.l/w: vd amx:9m;pe; sf.lf7p w The plane is inclined at an angle ol;7d fx9./vmmwlepa:p : fs ;wf $30^{\circ}$ with the horizontal. What is the object's acceleration?

  A 10-kg mass slides down alh esh,x6y6ob/k /h qyq xq(9* 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 plane witho*wula+-k /0 ab+w,cnn 87 hgqokmb2p 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 incline-k cxnj3b i6j4d 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 pla6+vwfug33l (tp kvi ;pzdxdbs-*j . s:ne, at a constant velocity of 6.0k+l(p3vzs ;fdw- pdv.xus*jgb3 6 it : 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 2mr(x3xi *h jdm slides 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 a rough t vpqsq5(xj,7 $37^{\circ}$ 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 auq )a6mtyy2ku,hc; e1 sy0p*rlong a rough surface. The cable attached to the log makes an pqym shetr6yc)1, k ya*;u02 uangle 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 rough inclined plane tilted at an anglk ,w) 9aw;5ls,pgqvjqe o glj, 5k)vw9qpa;qsw,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 inclined pl 4+wqgg pe3r5oane. The angle of incline is gradually increased until the object begins to slide. The angle at which this occurr3gpwgqo54e + s is q. What is the coefficient of static friction between the object and the plane?