Which of Newton's laws best explains why motorists shoul5wkz:b4rz z 9pd buckle-up?

  When you sit on a chair, the resultant force on you -jmr,b vz--o eis

  In the absence of an external force, a moving object a1)76 vt xrhmzwqqj.,,rfu4 lwill

  When the rocket engines on the starship NO-PAIN-NO-GAIN are sdc3 6ti r+f7hmdbe 6w.cbr1.suddenly turned off, while traveling in empty space7. wc+db 163.ihfbde c6mt rsr, the starship will

  A rocket moves throug3/rk 8fzjy9k i02zvqj;m up d2h empty space in a straight line with constant speed. It is far from the gravitational effect of any star or planet. Under these condit2m zp9izr0d2qj3k;jkv f8y/ uions, the force that must be applied to the rocket in order to sustain its motion is

  You are standing in a moving bus, facing forward, and8opskqw0vokpr5 2) r * you suddenly fall forward. You can impkw 8rop 5)o*rvk0psq2ly from this that the bus's

  You are standing in a moving bus, facing forward, and you suddenly fall) 1js s3y+swmv forward as the bus comes to an immediate stop. sjys) vs+mw 13 What force caused you to fall forward?

  A constant net force acts on an object. Descrifcn 0y.,k(1rwu*,jj b skr4 zmbe the motion of the object.

  The acceleration of an object is invers6ylnqfobv aum+/vsu/k* a;k;z-:e l 6ely proportional to

  A net force F accelerates a mass m with an acv *43 wj+c0nznvjn tj+celeration a. If the same net forcej3 +vjz40+jw* vtnnnc is applied to mass 2m, then the acceleration will be

  A net force F acts on a mass m and produces an accelr8, jd jg5aiwq)44 mzweration a. What acceleration results ij4g)dqj 5 wazmwi48 r,f a net force 2F acts on mass 4m?

  If you blow up a balloon, and then j3muo jn;hka, r /bsc01s.b n7release it, the balloon will fly away. This is sb0n13 j/sa,mnr7 uc .ko bhj;an illustration of

  Two cars collide head-on. At every moment during the collisifln0ius5p* ,oon, the magnitude of the force the first car exerts on the second is exactly equal to the magnitude of p5u0l*, ifo nsthe force the second car exerts on the first. This is an example of

  If you exert a force F on an object, the force which the object exerts on yol(9ld)ls0h ig4)b wrgc7 q/gju will4rl /cbshd9)g(q) l jl7g0w gi

  Action-reaction forcea +rc4evi+ 1jay2s.vw(dx9rhzz 9a0ms

  Action-reaction forces x18;f.3f1egsq krlv vare

  A 20-ton truck collides with a 1500-lb car an q)e5om rq1q)ld causes a lot of damage to the car. Since a lot of damage )mq5l1r e) qqois done on the car

  An object of mass m sits on a flat table. The Earth pulls on this )q8fchum4 cm 9object with force mg, whimfqu9c4)m hc 8ch we will call the action force. What is the reaction force?

  A child's toy is suspended from the ceiling by meaw:l/lc d k3e9wns of a string. The Earth pulls downward on the toy with its weight force of 8.0 N. If this is the wel 9/c k:3wdl"action force," what is the "reaction force"?

  Your bat hits the ball pitched to ym,orr*xu9q6 rou with a 1500-N instantaneous force. The ball hits the bat with6mru,oq*r r x9 an instantaneous force, whose magnitude is

State Newton's three lnrt k;h-0 p )d0tyllk3aws.

  Mass and weight

  The acceleration due to gravity is lower on the Moon thae b4k(/nvidyp h9* ,lbn on Earth. Which of the following is true about the mass and weight of an astronaut on the M, ie9nybkl(v4d/phb *oon's surface, compared to Earth?

  An example of a force which acts yr5kt.f-g qe3w dyk34at a distance is

  Who has a greater weigp ;cfauid:wv* ,/s.ooht to mass ratio, a person weighing 400 N or a person weighing 600cv;*d/sw.pfu i ,: aoo N?

  A stone is thrown straight up. At the top of its path, the netaj v v2ys8g5:g, wcmd7 force acting on it isyav:mj c g v,g8527wds

  A 20-N weight and a 5.0-N weight are dropped simultankemnd/+bw85dx ;w4jawdns8m u/ *1dveously from the same height. Ignore air resisu8k dbdewnj 8s/4 x1v /wm;man+dw*d5tance. Compare their accelerations.

  A brick and a feather fat8iwyw6*(qj n9 5qk gnsmua /nc8w 4(oll to the earth at their respective terminal velocities. Which object experiences the greater force of air frjq uiw8(6n*(aw o/9 c gmn8k n5ytqs4wiction?

  An object of mass m is hanging by a string from the ce;xg42g ekanywc ;m2 1oiling of an elevator. The elevator is moving up at constaneagy k o c1;42mx;w2ngt speed. What is the tension in the string?

  An object of mass m is hanging by a string from the ceiling of an elevatok*kbna 916sry /eezr (r. The elevator is moving upward, but sez*n ( 1kyrs/69 reabklowing down. What is the tension in the string?

  The force that keeps you fri7aq7ni;z dvq);3zdwom sliding on an icy sidewalk is

  It's more difficult to start moving a heavy cms t;a69/loxzarton from rest than it is to keep pushing it with constant szxt9;oa/ 6ml velocity, because

  A horizontal force accelerates a box from rest across a horizontb s5d 0vcf3i;ral surface (friction is present) ac 0db5i3fv r;st a constant rate. The experiment 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 dowo48hjx gu 764 jz31c2px nm-h6 hbvrzvn an inclined ramp at constant velocity. Thus we can dej 644xzhn 3j1gh v7z ucbovrhx-628pmduce that

  A block of mass M slides down a frictionless plane inclined at an vwhma+.y +v-t angle q with the horiz v-ta+ vhy+.mwontal. The normal reaction force exerted by the plane on the block is

  A block of mass M slides down a frictionles+p,oxxxqb3+0j(8 n 0bufi xees plane inclined at an angle q with the horizontal. The normal reaction force exerte +xxx3 eqjbnfp0bxu8i, oe(0 +d by the plane on the block is directed

  A block of mass M slides down a 7jfzrn)xc4lez(6e9o +wg a;rev wz/ : frictionless plane inclined at an angle q with the horiz4a:f)cvrxwg+zowe7er9 el;z j/ z 6(n ontal. The gravitational force is directed

  Two toy cars (16 kg and 2.0 kg) are released simultaneously on a f3:s5np1wltin inclined plane that makes an angle of 30e with the horizontal. Make a statemen1ftis3pl: 5nw t which best describes their acceleration after being released.

  An object sits on a frictio7spn0v/tc8,6,r3 b adpnl0pb / dlvcdnless surface. A 16-N force is applied to the object, and it accelerat0t87d cr0,bn3 p a cllpd 6pn/v/v,bsdes at $2.0 \; m/s^2$. What is the mass of the object?

  A sports car of mass 1000 kg can accelerate from reiv8q78xrz ;y3ql7vx dst to 27 m/s in 7.0 s. What is d87rz ;x87 lq3viq yvxthe average forward force on the car?

  Starting from rest, a 4.0-kg body reaches a speed of 8. b6eu0, /-sx nd ;fubtpxr:hk50 m/s in 2.0 s. What is the net force ac rd:pk su fx-6/neh05bxbut,;ting on the body?

  An antitank weapon fires;yf nxi8j8asgb yp+ g;3k+;vf a 3.00-kg rocket which acquires a speed of 50.0 m/s after trave ybpaj g;8s3f;g+vi f k;x8y+nling
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 mass frs.e7:9tquitje44**+7 hkws cws kwr wom rest,wei7s*kjweh+ wwq u9s:r.s474tc t *k

  What is the mass of a persoe2/hbs1bly 9wo/(go tn who weighs 110 lb?

  What is the mass of an object that weighs 250 N on the surface of the Ea5q4tin4h p9s r7ssr)r dbwq :;rth where the accelerationqrd s w54s;r):74 9nisphbqrt 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 objectw .*9 ucqlp,fn8jmfd8 on the sur uw jfq*cm8d9lp., n8fface of the Moon where the acceleration due to gravity is only 1/6 of that on the Earth?

  Object A weighs 40 N on Eaf .*4k/ syr loz0uhqwlcy7-y/rth, and object B weighs 40 N on the Moon. The Moon's gravity is one sixth of Eak*7y/y/z-uwhf ryoq sl 4 l.c0rth's. Compare the masses of the objects.

  Sue and Sean are having a tug-of-war by p nqsc5-mwm1 , uwr-9w-3vea uaulling on opposite ends of a 5.0-kg rope. Sue pulls with a 15-N force. What is Sean's force if the rope accelerates toward Sue at uas13 -,c5w n wmv- qra9e-wum$2.0 \; m/s^2$?

  A stack of books rests on a level frictionless surf 1ku8a+vx mqt2ace. A force F acts on the stack,um+1 k tv82qxa and 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 standsnf e 0gbjj)kj6 yf51:h on a scale in an elevator. What will the scale be reading when the elevator is accelerating downwafjg5j 1)06e fjbn: yhkrd at $4.00 \; m/s^2$?

  A person on a scale rides in an elevator. tjx-(ym;c 5o 26oux2son .jv q If the mass of the person is 60.0 kg and the elevator accelerates down.x2o jn mqts j;c52(ox6y-ouvward with an acceleration of $4.90 \; m/s^2$, what is the reading on the scale?

  A person on a scale re9uku 5t)lcx6,qb lk z63upt. ides in an elevator. If the mass of the person is 60.0 kg and the elevator accelerates upward with an acceleratiu,buzlt3x56k.uk9q6l)c pe t on of $4.90 \; m/s^2$, what is the reading on the scale?

  Two horizontal forces act on a 5.0-kg mass.qekw/ tgl9hg7.bs( 2z One force has a magnitude of 8.0 N and is directed due north. The second force toward the easwsbet9g q 7g z2l.hk(/t has a magnitude of 6.0 N. What is the acceleration of the mass?

  An object of mass 6000 kg rests on0; pb1/.g(3t/ 35kboevjntk nol mccd the flatbed of a truck. It is held in place by metal brackets that cam3dtkkc cte/j5n bobl;v 10ng(.3/opn 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 into the cab?

  An object of mass 6000 kg rests on the flatbed of a trucx ,onwq si.3l+w*qdc8k. 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 time if the load is nw l +8.qn ,o*dcixws3qot to slide forward into the cab?

  In the Atwood machine t.s;zh* + 3pus g1ztcmshown in Fig. 4-1, if M = 0.60 kg and m = 0.40 kg, what is the magnitude of the;g3*1 st+hp zsucm.tz acceleration of the system? (Ignore friction and the mass of the pulley.)

  In the Atwood machine shown in Fig. 4-1, if M = 0.60 kg and m = 0.40 kg, what iu gnzbzmg;w(0 v 3j6+xs the tension uwnzj3zg ;6x mg0vb+( in the string? (Ignore friction and the mass of the pulley.)

  A student pulls a box of books on a smooth horizontal floor with ss 7mq lg)4x.sf-ulk8a force of 100 N in a direction ox8u gsl 7-lk) 4fqm.ssf $37^{\circ}$ 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 r,fzsm(xa/rhq- o7, s 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 the b,/sazrf (7 qsxm,rh -oox?

  A traffic light of weight 10 ag4, -m20rasghao5rj0 N is supported by two ropes as shown in Fig. 4-2. What are the tensions ingoa,5 j-hm2r agsra04 the ropes?

  In Fig. 4-2, if the tensions in theo./(60kh7faix o svng ropes are 50 N, what is the mass of the traffickf6gsi o7h./x (0avo n light?

  Two boxes of masses m and 2m are in contact with each other on a fri -b3 xt62hy)fr0b x:tac;dka qctionless surface. (See Fig. 4-3.) What is the acceleration of the morhax6 fyd rct )3t2 0-;k:bbxqae massive box?

  Two boxes of masses m and 2m are in contact with each ot kzm z 49tt9b/+.uzrgsher on a frictionless surface. (See Figrtkzmz9+z 4 s./9tbug . 4-3.) What is the net force on the more massive box?

  Two boxes of masses m and 2m are connected by 4khv h.nq59f* ,gdcs ba rope. (See Fig. 4-4.) If the forward force on the more massive box . f ,hvnbsdc*5hqk9g4 is F, what is the tension in the connecting rope?

  Two boxes of masses m and 2m are con */i:z(d nhqysnected by a rope. (See Fig. 4-4.) If the forward force on the more massive box is F, what is t:q* /zi (ydhsnhe acceleration of the less massive box?

Two boxes are connected by a cori2q 1atv se*obn3(no/qt )fc2ny-np .d running over a pulley as shown in Fig. 4-5. Box I of mas(y1nson)foneb -*itv3t2q cnap q/2 . s
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 and a desk + ,;kemlvhq8g x7 p) f4j31t;geu oljyare 0.40 and 0.30, respectively. What is thee8oy)1 xm v43 +;qkefj;gg7l, l phutj net force on the box when a 15 N horizontal force is applied to the box?

  The coefficients of static and kineticuobf;76 epfa mc22 xx) frictions for plastic on wood are 0.50 andf2 xboe)mp cx67 fau;2 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 in+n5ex 5lzj37fe+h ora the +x direction. It slows and comes to a stop with a cx7n5++f35erl azj e hoonstant 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 trsdb40rv l2v)6nd,z surface is pulled by a 5.0-N force. A 3.0-N friction force retards the motion. What is the acceleration dnl64d zb) tvvr20s,r of the object?

  A horizontal force of 5.0 N accelahws94 cchu 63erates 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 *b4(fcj,ms : yf:nelh96zv4r x a6tso, a puck 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 puck and th*m , lsnxf f s r4c4tz6(6:9ayejbv:ohe ice?

  During the investigation of a traffic acci/ p/ tyg enb.9m-p)mczdent, 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 prevailing conditions. Estimate the speed of the car tp.ybcg pe 9/nmm)z/- when the brakes were applied.

  Two boxes of masses m and 3m are stacked. (See Fig. 4-fg5m3rollt-q vio20 ,ad- tn86.) 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 doe2r ,mv0oftda q g3ol5tn8--lis 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 stacua: uj qj2gezv *wm+/7ked. (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 sl7 u 2ga:qwj +z/vejm*uide on the more massive box, what is the coefficient of static friction between the boxes?

  An object is on a frictionless inclined plane. Thei qj-grcg)a(tcw1n86 /r.zy e plane is inclined at an angle of .ctzr18j/ r ea iycq-gg6)wn( $30^{\circ}$ with the horizontal. What is the object's acceleration?

  A 10-kg mass slides down a flati/w 7p3nvf o-irasb.1 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 sm-s; z/xaqtt (yooth 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 smoo,cupm z1-jewzz/ q1 /dth 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 directlyd(l08sg0 u b- uqpakx+ down an inclined plane, at a constant velocity of 6.0kb xl0a0 8-p(usqd+ ug 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 doa8 f*nt3dmf)yv)f1 z8xhpk 6ewn 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 h )h6m:p .fmpt$37^{\circ}$ 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 N6tiaq 3doj. vjnr4l3;q ); xhb along a rough surface. The cable attached to the l;4ad3.qq bjnt l3iv)o ;jh6rx og makes 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 rough inclined plane tilted at an a9e /k+tqnqc (z4n*mijb7c)z kngle obzk*qqc)(/e9k7 4 zn +ictn jmf $33.5^{\circ}$ 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 gradualli, x:n /c(cjxkx4wuj,y increased ni4/xwc(jj, ,c xk ux:until the object begins to slide. The angle at which this occurs is q. What is the coefficient of static friction between the object and the plane?