Which of Newton's laws best explains why motorists should bepa wy(8cei32e ;bpd, b.hb8 puckle-up?

  When you sit on a chair, the resultant force on yq*vd m:b )i9 xzs (p/xi.tvhfm)y6( otou is

  In the absence of an external forc;b wiy.szo9i /ml y;h0bs;(wmsau i 9ag9;lc5e, a moving object will

  When the rocket engines on the starship NO-PAIN-NO-GAIN are suddenl 2kwsnh,3 -wje tnt4wcmr 4)wty1(hc,y turned off, whih t1m4, nsc-wt ),w kyewrt3h4n2c(jwle traveling in empty space, the starship will

  A rocket moves through empty space in a straight k6g/z68cf+la e m t-jrline with constant speed. It is far from the gravitational effect of any star or planet. Under these conditions, the force that must be applied larkj+tf m66cez-8 g/to the rocket in order to sustain its motion is

  You are standing in a movin6vf/ cs a*kem*/8 3qjyxx9 yhbg bus, facing forward, and you suddenly fall forward. You can imply from this that the bus'syk8c/ x b x*ajeq v9f6*3ym/sh

  You are standing in a moving bus, lifgs */ewmfk4+i .r4facing forward, and you suddenly fall forward as the bus comes to an immediate st*imw.ile fg r4 /4s+kfop. What force caused you to fall forward?

  A constant net force acts on an object. Describe the motion of t35oz31az srdy1wem;y he object.

  The acceleration of an object i3 0yqd,7e1iav*e sgtbq-y,jys inversely proportional to

  A net force F accelerates a mass m with an acceleration a. If the same nkhu:d2 r+ ;ks zmiii qp,736mnet force is applied to mass 2m, tiknr+;pkmi :23 i, sh7zq6udm hen the acceleration will be

  A net force F acts on a mass m and produces an acceleration a. What acceleraxxcl 9q;-x ic-tion results if a net force 2F a9qcx x-ci-;xl cts on mass 4m?

  If you blow up a ballou:e8 +1 tivbjt/m. xmion, and then release it, the balloon will fly away. This is an illustrationitvbm:+ .umji8 x/ 1te of

  Two cars collide head-on. At every moment during the cog qpnn.,zu 8ui2xg ( tpl+o-s*llision, 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 ot2s+zq ni *n gp-(glu8 u.x,pthe first. This is an example of

  If you exert a force F or*ge. onltd.z qn;k,k n9.lhqu0f5qc 6c g)d)n an object, the force which the object exerts on you willn.qlccz5 0n;gh)k k t,*)6d.qo 9glq drn.eu f

  Action-reaction forcewy-qy1q: fo 12vg75bdu(24b eu gsvlas

  Action-reaction forces aman):uf3vpc4lmb z l3*2 c7osre

  A 20-ton truck collides wir)pk8k3e h*,/ *ogkewg bk1 ldth a 1500-lb car and causes a lot of damage to the car. Since a lot gbg8e*) 1,lwe/krdk hopkk3* of damage is done on the car

  An object of mass m sits on a flat tabldim f - 2bwp3l.ma4wk,e. The Earth pulls on this object with force mg4fa2 wl.mk3bdi-wp,m , which we will call the action force. What is the reaction force?

  A child's toy is suspended from tha)c grazrn(c. 0prmwq70p b(uey) i,1e ceiling by means of a string. The Earth pulls downward on the toy with its weight force of 8.ap,myr c)e)ac1p0gwbz 0.r ri(q(7un0 N. If this is the "action force," what is the "reaction force"?

  Your bat hits the ball pitched to you with a 1500-N instantaneous force.- pdwnmcru )gp x2.21mm4)vob The ball hits the bat with an instantanw-nmr2dv)m 4ocmpp b u2 x.1)geous force, whose magnitude is

State Newton's three labnq j.f...uqv8 )(fy9rakh xsws.

  Mass and weight

  The acceleration due to gravity5eqha6 bmt9 ;z 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 surface, comh6z 59 eabmtq;pared to Earth?

  An example of a force which acts at a distancexsk6h*w 9er;xl 4 ib+b is

  Who has a greater weight to mass ratio, a pes0b0)pdq i7 s7il o(aan6g;xqy v;4ut ,qsmt+rson weighing 400 N or a person weighing 600 qy ;x4nqiq (6gibvt 7u)l m,;7sotp a+0ss a0dN?

  A stone is thrown straight up. At the top of z0 ptzy p86n)cv(of0dits path, the net force acting on it i y 8co)zp0tznpf6v0(ds

  A 20-N weight and a 5.0-N wei)edeimb e2 2fvr3dc :*ght are dropped simultaneously from the same height. Ignore air resistance. Compare their acceleratce2ef:32 dmbvrid) e* ions.

  A brick and a feather fall to the earth at their respective terminal velocccep5c .wvw. 7ities. Which object experiences the grv.wccp7wc5e . eater force of air friction?

  An object of mass m is hanging by a strq6y i5br uj /e.rkh3*cing from the ceiling of an elevator. The elevator is moving up a6c/beiu*r. ry5j3q kht constant speed. What is the tension in the string?

  An object of mass m i.:(-blwkydow3 g9oyt s hanging by a string from the ceiling of an elevator. The elevator i :owtbg -9olywd3.ky(s moving upward, but slowing down. What is the tension in the string?

  The force that keeps you fri lm+jaf45 9ipom sliding on an icy sidewalk is

  It's more difficult to start moving a heavy carton frvtuabhw4fs0g,lj u e, .1p *0*u:hvn oom rest than it is to keep pushing it with constant velocity, b.v fub v :,u,*j4uptsho0 hg1e0w al*necause

  A horizontal force accelerates a box from rest across a horizontal surface (fr27ru;: s,gxp zewxd9ciction is present) at a constant rate. The experiment is repeated, and all conditions remd2p swgz,r uexx;9:7c ain 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 velocity. Thushp ic) f (3*akf.gqye, we can deduce t3 ygfep,ck ia*.qh (f)hat

  A block of mass M sli kuk7u 0xe6cgysrgrn9s6 4 g.,des down a frictionless plane inclined at an angle q with the horizonta6gsy7ekc4n69 0.gsg,u xur r kl. The normal reaction force exerted by the plane on the block is

  A block of mass M slides down a frictionles*sn2k b)ro.tss plane inclined at an angle q with the horizontal.rs)bot2*k s .n The normal reaction force exerted by the plane on the block is directed

  A block of mass M slides u28k1nu,jsc6:w .ugh0id2)8 + iz woy xxmwhk down a frictionless plane inclined at an angle q with the horizontal. The gu 8k1ug ) o2usjk2di :y0.z wh xh+86wm,ciwnxravitational force is directed

  Two toy cars (16 kg anj)s f; a:r:qqtuc3(ywd 2.0 kg) are released simultaneously on an inclined plane that makes an angle of 30e with qfy: 3(q;jracwu)s:t 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 a nix 1d/1a;(in*xuu lrpplied to the object, and it alx1uxdinau(;n*ir 1 / ccelerates 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 7ix;wys62.+x jw+z*s6ow nu uq .0 s. What is the average forward force on t u+j .nyu6 6sx ;qwswx+zi2w*ohe car?

  Starting from rest, a 4.0-kg 2 sxmh+91rzv c9s,ho cbody reaches a speed of 8.0 m/s in 2.0 s. What is the net force acting on thmv2r 9hs x9c hzos+,c1e body?

  An antitank weapon fires a 3.00-kg rocket which acquires a speed of 50.0 m/s 1n3scpcnovil8. ) g.;pnjzy0 after traveling i0zpl1cj;o83. vynsc)p n n.g
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-kg ma +yxvv5ug/xm2 kpm9)css from reu /kx)p5vym2cg 9xmv+st,

  What is the mass of a person who weighsv)2p2 n hdfoi7 110 lb?

  What is the mass of an object that weighs 250 N on thqet/x+ap.l3 b2m5d a9 e tin+he surface of the Earth where /tq+t9. +i2ha5lmnb3padexe 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 mas,nooj/.e,u yu s of the object on the surface of the Moon y/. noe u,,juowhere 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:h9 jje)jzzd)gn+zcw7z4i8s,x -b g g Moon's gravity is one sixth of Earth's. Compare the masses of th zi gsbh8z )n7g9-jc jx4,zjzgd:we+) e objects.

  Sue and Sean are having a tug-of-war by pulli gy . 9k-ivk8m32kuf6rg4tprgng on opposite ends of a 5.0-kg rope. Sue pulls with ggvfky9kr4.8 t2gk- iu6rm3pa 15-N force. What is Sean'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 f o xtg-wa )muk0*wrs47. qp5inv9j mm0orce F acts on the stack, and it accelerate 4i pt7njk5mwsg*q)x0v-u0m r .oaw m9s 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 stanmuay5 d9c feuaz/81 q/ds on a scale in an elevator. What will the scale be reading w/8ud5m/auyafqec z1 9hen the elevator is accelerating downward at $4.00 \; m/s^2$?

  A person on a scale rides in an elevator. If the mass of y)fkzz)q tr)z z6w0m( the person is 60.0 kg and the ewq )z 6zzkm zy(rf0t))levator accelerates downward 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 ma 3equ 4xn:d1h*nc lk*amqh/(9lfc za/ss of the person is 60.0 kg and the elevator accelerates m 9f nk*4:/e u(aalcq zl1 /3xnh*chqdupward 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 h ird k6b4:l/amass. 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 accela/kb4lrh: id6eration of the mass?

  An object of mass 6000 kg rests on the flatbed of a truck. It is p y4(dxnl/5f srm8.7y5pfi cfheld 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 distannixffl f45s 8cp/d5y .yr7m (pce if the load is not to slide forward into the cab?

  An object of mass 6000 kg rests on the flatbed of a truck.e 8b6uvv(h d1e 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 miv ( ev861uedhbnimum 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,zh7j/mu s)/a p what is the magnitude of the acceleration of s m)zua7h/ j/pthe system? (Ignore friction and the mass of the pulley.)

  In the Atwood machine shown in Fig. 4-m -m b5.0c *8yh2wnbx1lfwfrg 1, if M = 0.60 kg and m = 0.40 kg, what is the tension i8.gb1n*w m5rl xb0f2f chwm-yn the string? (Ignore friction and the mass of the pulley.)

  A student pulls a box of books on a smooth horizontal floor with a forcn7 58q ee*ld)5 ied)gu ya:.3jouwuet e of 100 N iagj)7tu .ye:uwdue o8q5le e53)*dn i n a direction 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 o ,ylnn ;*lq jqlc6;(kmf books on a smooth horizontal 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 normal force on thejllk;n lq,myc(6;*q n box?

  A traffic light of weight 100 N is suwpw2i*/ s-ee +vhck.fzg f: d;mv(e3ypported by two ropes as shown in Fig. 4-2. What are the tensions in t3g ewvysd.e- (h/;:2e cz ifwf vmk*p+he ropes?

  In Fig. 4-2, if the tensions in the ropes are 50 N, what is the mass ynlloe mj1 n-c1ue,(s22 dw,h of the traffic,2sned 2jh n-ou wyl, ecl(m11 light?

  Two boxes of masses m and 2m locfzl0f w-.ll6b 15efxu . u/k:k-ap are in contact with each other on a frictionless surface. (See Fig. 4-3.) What is the acceleratpc 5-ex/u1l.o0:.ll6w ufbl-kz f akfion of the more massive box?

  Two boxes of masses m and 2m are in contact with each other on a fricti7l2c:s l uhh4konless surface. (See Fig. 4-3.) Wh 2l7 hs:4ckhulat is the net force on the more massive box?

  Two boxes of masses m and 2m are connected7be s-ny,aap 5 by a rope. (See Fig. 4-4.) If the forward force on the more massive box is F, what is the tension in the connecting s-y an7a5eb,prope?

  Two boxes of masses m and 2m are connected by a rope. (See Fig. 4-4.) If the fr0qz2x2up ng zo-l )s/orward force ol) sx0/2rzz qg o2-punn the more massive box is F, what is the acceleration of the less massive box?

Two boxes are connecteyy0lwn( text6/mwsu ) kb(u7:0vin .h d by a cord running over a pulley as shown in Fig. 4-5. Box I of m /xny hbe. 0wiw()vun0:u tks7l 6(tmyass
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 kineticpd.lz8 :cnb;z 5nfo:rf47i i c frictions between a 3.0-kg box and a desk are 0.40 and 0.30, respectively. What ip 4 75:dzlnc8 z.:fifbor;cnis the net force on the box when a 15 N horizontal force is applied to the box?

  The coefficients of static and kinetic frictions for plastic on wood are sz:dj*ca/ f7i 0.50 and 0.40,ic 7j:azs fd/*
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 i; )e )nqe;h)ad stmcd9n the +x direction. It slows and comes to a stop w ;)hndtedqms c;)a9) eith 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 pullzk0es *pq 2v4yed by a 5.0-N force. A 3.0-N friction forckq p*v y0e2z4se retards the motion. What is the acceleration of the object?

  A horizontal force of 3uuhudgclns58+ , y6y 5.0 N accelerates 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 give)f5khy 5fh.e fn an initial speed of 10 m/s. It slides 50 m on the ice before it stops. What is the coefficient of kin5fffkh5e .y)hetic friction between the puck and the ice?

  During the investigation of a ty68qy:8k7 wnbar- humq a1i7o raffic accident, police find skid marks 90.0 m long. They dete 8ybyo7 ukq7arwi-q m1h a6n:8rmine 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 surfac++z hnpytvsb 8u:9o1 de between the more massive box and the horizontal surface is smooth and the surface betu p+no9 +:tsv zdb1y8hween 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 and 3m are stacked. (See Fig. 4-6.) The surface between yaj ch -zi+s xuan5k80e d203tthe more massive box and the horizontal surface is smooth and the surface between the boxes is rough. If the j+uenth scki2 ax30y5a z0-8 dless 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 frictionl (; tg40oi7wxlcdsv8n ess inclined plane. The plane is inclined at an anglixcg;l wd(8v07 snot 4e of $30^{\circ}$ with the horizontal. What is the object's acceleration?

  A 10-kg mass slides down a flat hill that makes an angl,d pzsn rmvdzj4,ypk0kj;v6gf cbh+0 l ;5c) 5e 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 ang tl*z)s0 (xbknle 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 plane tilted at an angle ofbs/aayo d .;6dgbv./ g $35^{\circ}$ 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 directlz0rb , n3qe*, lzny,.hkrerp (y down an inclined plane, at a constant velocity of 6.0 eh,ken,*lqn b. 03r,(yzpr z rm/s.
What is the coefficient of kinetic friction, if the plane makes an angle of $25^{\circ}$ with the horizontal?

  An object with a masr avop91mj 0b9;nfyy,s m 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 akie5ga)l6j*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 weighi (n)svyq4sqs+ng 500 N along a rough surface. The cable attached to the log makes an as4qsq ns(v)y+ ngle 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 tip80xnt;x(ocj2odh 5: 1oc miwlted at an angle ofhmj o(ctci;5 018 onpxx:o2 dw $33.5^{\circ}$ 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 incli vl m)9z1;yqluvy (ja+ned plane. The angle of incline is gradually increased until the object begins to slide. The angle at which this ou qlz;v19ja l +v()ymyccurs is q. What is the coefficient of static friction between the object and the plane?