Which of Newton's laws best explains why motorists sh(xsr6 itpc2,7 4 kpqumould buckle-up?

  When you sit on a chair, theb+dor);bt k on (fce:- resultant force on you is

  In the absence of an external for7 orl/z.ii9db(.let5c9w fau ce, a moving object will

  When the rocket engines on the starship NO-PAIN-NO-GAIN are-wskq6ska0k 7k fg.e8 suddenly turned off, while tra7qk - kk6sfk08ewg .saveling in empty space, the starship will

  A rocket moves through empty space ij a w,gw,w3oo:,c4roc 8 dq,dy1n/xcyn a straight line with constant speed. It is far from the gravitational effect of any star or planet. Under tcwx,o 3/, og y4conq r18dcwwy:ajd,,hese conditions, the force that must be applied to the rocket in order to sustain its motion is

  You are standing in a moving bus, facing for* 8uxfntdicc1s6 f)+qward, and you suddenly fall forward. You can imply from this fs1cc )q+d xu6n*t8if that the bus's

  You are standing in a moving bus, facing forward, and you sudd a.x tpoxm .y45bism1:/aab 7ienly fall forward as theobx51paa./mybxa m:s7it 4i . bus comes to an immediate stop. What force caused you to fall forward?

  A constant net force acts on x8y)ze9 dx ng8an object. Describe the motion of the object.

  The acceleration of an object is invers x j-/fc8q oeu5j j +2n7f-y8npq7qympely proportional to

  A net force F accelerates a mass m with an accelerat5ua .owyeyc )1 mkn64hdn;oc 7ion a. If the same net force is applied to mass 2m, then e.dyh); yomu canw6 co41 75knthe acceleration will be

  A net force F acts on a mass m and produces an acceleration a. What accelerat2vknpx 5*9l ueion results if el9ukvnp2 *x5 a net force 2F acts on mass 4m?

  If you blow up a balloon, and then release it,uop f v 94w96oee/vm5c the balloon will fly away. This is an illustration w9 9uevocp5/ov e6m4f of

  Two cars collide head-on. At every moment during the collision, the magni6nbuc u+ 4d3tftzny27ag8t5xzh8 n5htude of the force the first car exerts on the second is exactly equ2hgzat y5n8z7 nbcn+3 txu t5 d6hfu84al 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 object, the force whia(6y xy 1w2bxgch the object exerts on you willga w(x26byy1 x

  Action-reaction forces na 6q6cff/d9w

  Action-reaction forces are lrb oyc6p n4u0 (+ifxp)u7 0o-crkr5v

  A 20-ton truck collides with a 1500-lb car and causes a lot of dam,oe duu: kk-qrzfe9p +pu))4f age to the car. Since)9pk up) qforf4e-udz,ke: u+ a lot of damage is done on the car

  An object of mass m sits on a flat g+ zqqn uptj)32*-u,v rh3ifbtable. The Earth pulls on this object with force mg, whu3ju+*2frb i z gth- 3p),vnqqich we will call the action force. What is the reaction force?

  A child's toy is suspended from the ceiling i0+bk yx8g7olby means of a string. The Earth pulls downward on the toy with its weight force of 8.0 Ngiy+o807 bxkl . 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. Thetd(cftt) dqk -iz;b7+ ball fqi(-d ;7cbt d)+kttz hits the bat with an instantaneous force, whose magnitude is

State Newton's three ll -xkow0+9xkue m4et -aws.

  Mass and weight

  The acceleration due to gravity is lower on the Moon than:ng 1 *xu5udy7fldb(z on Earth. Which of the folly (xd7*un :ublgzdf 51owing is true about the mass and weight of an astronaut on the Moon's surface, compared to Earth?

  An example of a force which acts at a distance l 1sh7n1a7t 6 kw7ffh7fydngi *we9z0 is

  Who has a greater weight to mass ratio, a person weighing 400 N or a buz qxyq:0 0w;w ;ef-) u-bheyperson weighing 600 0h q ewwbbuq:;; )zu-yfye0-xN?

  A stone is thrown straight up. At the top of its path, the net forcrcuuwu.m)p,s:( b9ixe 91g f ze acting on it is 1zxu:su.bgc)imf r( ,w99pue

  A 20-N weight and a 5.0-Nw 3b1 9sqooh4/r (qiy yghrq/( weight are dropped simultaneously from the same height. Ignore air resista h1/gi3bw4yqr( sh(q oy/9oqrnce. Compare their accelerations.

  A brick and a feather fall to the earth at their respective terminal velo/dix* )(wo(hks rp5ii+a 4ihmcities. Which object experiences the greater force oi(ohi4sma piidw/h+ kr)5 (x*f air friction?

  An object of mass m is hanging by a . uip.:l 7jfxhv0ohs-string from the ceiling of an elevator. The elevator is moving u.ih0fl :x7 vu.h jpso-p at constant speed. What is the tension in the string?

  An object of mass m is hanging sxbi xb7rz**+hs3 s (kby a string from the ceiling of an elevator. The elevator is moving upward, but slowing down. What is the tek ixs *x(h bb7s*rz+3snsion in the string?

  The force that keeps you from slidingd fux +oj( ;m)w.t+joq on an icy sidewalk is

  It's more difficult to start moving a heavy g/+2wewn7kjbeo+; cw carton from rest than it is to keep pushing it with constant;eko2cewj+ b+/n7 wwg velocity, because

  A horizontal force accelerates a box from rest across a horizontal su:wpx/ g*di /xc8m s7adrface (friction is present) at a constant rate. The experiment is repeated, and all conditions remain the same g px8mdc:d*w/sia x/ 7with the exception that the horizontal force is doubled. What happens to the box's acceleration?

  A packing crate slides ds7k o bus4)ar4(lw4fkvswm8 3own an inclined ramp at constant velocity. Thus we can deda484kk s ww(rssf437)voumb luce that

  A block of mass M slides down a frictionless pl+v12ymyu3 k 6ctuje- lane inclined at an angle q with the horizontal. The normal reaction force -u3ukve2+cmtjl1y 6y exerted by the plane on the block is

  A block of mass M slides down a frict2vq3ad x qnh;cg 4s+2nionless plane inclined at an angle q with the horizontal. The normal reaction force exerted by a+ 2n2 q;gvdch4qsnx3 the plane on the block is directed

  A block of mass M slides down a frictionless plane inclined at a p8zmp+rgi4wh91m 8il n angle q with the horizontami1lpzi84 hm8w+9g rp l. The gravitational force is directed

  Two toy cars (16 kg and 2.0 kg) are released so nww)14ko*bcz xb f9)imultaneously on an inclined plane that makes an angle of 30e with the horizontal. Make a statement which best describes their acceleration after bz4o *c1k xbno))9ww fbeing released.

  An object sits on a frictionless surface. A 16-N w5;o(noasxe 1 -huqf0w 85 bytforce is applied to the object, and it acu0- n5 aex1bf;8qyh o ow5(wstcelerates at $2.0 \; m/s^2$. What is the mass of the object?

  A sports car of mass 1000 kg can accelerate from restca xt3ckc4 n13a8qc;7ejmv6yg y9* vj to 27 m/s in 7.0 s. What is the average forward force on the car?9kjva c anx y7mc4*vg86 t1jecyc3;q 3

  Starting from rest, a 4.0-kg body reaches a spegg* i92ny cfdk9 7 xthd -ujwufi41w*/ed of 8.0 m/s in 2.0 s. What is wgw9gk 9fhf4-1xtjn iy *2ucddu*7/ithe net force acting on the body?

  An antitank weapon fires a 3.00-kg rocket which acquires e 0 wdgw*l ) i4puhr+zh:o6mik1jy4t5 a speed of 50.0 m/s after travel g 6r0eh u 44yh+*1wdz)moii:k5 lwtjping
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 witho9n)(x fuko. v the same force that you push a 10-kg mass from rest,9 uo)knx(fov.

  What is the mass of a pea ) z1bv3gt;firson who weighs 110 lb?

  What is the mass of an objectz5mw(k m.;s u-ewxdqzf63e f8 that weighs 250 N on the surface of the Earth where the acceleration due to gravit (ws;z8zx- e3fwmd .fkq56emuy is $9.80 \; m/s^2$?

  An object has a mass of 60 kg on the Earth. What is the mass of thh yykcprxa;7e / vs/:9f0*gfxe object on the surface of the Moon where the acceleration due to gravity is */yh/kc 7x; 9pa0rx y ffv:gesonly 1/6 of that on the Earth?

  Object A weighs 40 N on Earth, akav8,rv; :zy(nsr r5un;mb sa3a c r*7nd object B weighs 40 N on the Moon. The Moon's gravity is one sixth of Earth's. Compare :k 7br ravru,;a8*5n3syscrnv;(amz the masses of the objects.

  Sue and Sean are having a tug-of-war by pu84 lmyk6(4- ,lzgx monnrw,cilling on opposite ends of a 5.0-kg rope. Sue pulls with a 15-N force. What is Sean's mn(,gmolky4z6,w ncr x4l 8i-force if the rope accelerates toward Sue at $2.0 \; m/s^2$?

  A stack of books rests on a level frictionless surface. 8q vn 8n*h4rdci t((sx.ui4g j A force F acts on the stack, and it t8x dvn( quih(.rjsc44ng8 i*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 scale in szy 69i . wm 3-9qf csj*+wgnesx7jns)an elevator. What will the scale be reading when the elevator is accelerating downward q 9cswy 7j. ssx-3 )fiw+nej9mgz6sn*at $4.00 \; m/s^2$?

  A person on a scale rides in an elevator. If the mass of the person is 60 is7yuhe5k +t-.0 kg and the elevator accelerates downward with -iskt+5h u7ye an acceleration of $4.90 \; m/s^2$, what is the reading on the scale?

  A person on a scale rsd;.vdicg 24)z m uh.yides in an elevator. If the mass of the person is 60.0 kg .s4 d2d;c.hzv)iygum and the elevator accelerates 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 a magnitude oqp2ewff5uw8hjia7 z 6-yxh; .f 8.0 N and is directed due north. The second force toward the east has .a7q w-fz ep5f 62x whi;hjuy8a magnitude of 6.0 N. What is the acceleration of the mass?

  An object of mass 6000 kg rests on ty nv3o,x xau/4n9pz;ehe flatbed of a truck. It is held in place by metal bre 3xv;z 9np4,xany /ouackets 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 into the cab?

  An object of mass 6000 kg rests on the flatbed of a truck. It is held in pljc-ux6f r vp9w i53 h0sx ahp9ri33pc0eg-lg2 ace by metal brackets that can exert a maximum horizontal force of 9000 N. When the truck is traveling 15 m/s, what i0sg0 f2 w l3cpi-p3-xe53ughr9cj9vx 6 hrapis the minimum stopping time if the load is not to slide forward into the cab?

  In the Atwood machine shown in Fig. 4-1, ifzg+7f tt./;t ci+9*i v7qosbbh, jokt M = 0.60 kg and m = 0.40 kg, what is the magnitude of the acceleration of tcbzt , t.q7th9to+;vikf*igb js+ o7/he system? (Ignore friction and the mass of the pulley.)

  In the Atwood machine shown in Fi d03gi jh3h0 y(1z i czwi1i-tayxve56g. 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 the630jhzahigidc 5zi30x 1ye -tv 1(w iy pulley.)

  A student pulls a box of books on a smooth horizontal floor wit9 wk(oq,i uj9ch a force of 100 N in a direction of jio9 q9(,kuwc$37^{\circ}$ 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 forc0r9c+sluh/u;9 lqwrg,ts6 nk e of 100 N in a direction of 37.0n,rgc k6 l+ t/lqhru9 9u;ssw0e 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 supported by two ropes as s5u8*o7e ttbxr hown in Fig. 4-2. What are the tensions in 5oe87tt xbu*rthe ropes?

  In Fig. 4-2, if the tensions in the ropes are 50 N, what is the la.6 ba 5 qzg73ts3w+glj rg2xmass of the traffxzs jlgg26q7+b5g33 rata w.lic light?

  Two boxes of masses m and 2m are in cont2d x2j/*ixwd mmmgk 39act with each other on a frictionless surface. (See Fig. 4-3.) What is the acceleratio xi/3dw9jg2 d2 *mkxmmn of the more massive box?

  Two boxes of masses m and 2m a*g 7ot0rh4jiore in contact with each other on a frictionless surface. (See Fig. 4-3.) jo0hio7r*t4 g What is the net force on the more massive box?

  Two boxes of masses m and1anhve -h(hn+5ibz w : 2m are connected 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 ropen(zhw: h+5be1 v-ihan?

  Two boxes of masses m and 2m arpd i1d o4b76uue connected by a rope. (See Fig. 4-4.) If the forward force on thu d7du6 4pbi1oe more massive box is F, what is the acceleration of the less massive box?

Two boxes are connected by a cord running over -ovv*t +sc mg0+9jqqq a pulley as shown in Fig. 4-5. Box I of masg0q 9qv- tv q++oscm*js
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 fr:.0bm/yvkrk -o: iw( vl0z fi t9eja*iictions between a 3.0-kg box and a desk are 0.40 and 0.30, respectively. What is the net force on the bo jb .:i*eoriy:t9k 0v l(m/zikwv0af-x when a 15 N horizontal force is applied to the box?

  The coefficients of statd;/xbch0md l )d.nm-p ic and kinetic frictions for plastic on wood are 0.50 and-;d) cxn pld/mh0m.bd 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 j9kxy:,clp8)aj 3uj6d hhhds0g hi, ux0s r79a level surface in the +x direction. It slows and comes to a stoh upl, jh gj0scxuar :is09 k hx8,79h36dy)djp 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 pulle rgw p1 r2ww-x:qxmm:(d by a 5.0-N force. A 3.0-N friction force retards the motion. Wr xxgm-qw1 rmw:2p:(what is the acceleration of the object?

  A horizontal force of 5.0 N accelerates a 4.0-kg mass, from rest, at a htln 6 hpo*ig)5a; +axjk68hv/+v5jtv1 pwyvrate of $0.50 \; m/s^2$ in the positive direction. What friction force acts on the mass?

  During a hockey game,p1ekj7l; q1 l-:xsjwbsq 3io( a puck is given an initial speed of 10 m/s. It slides 50 m on the ice before it stops. What is the coefficien1 e;sil(jqjswolp 3-:1x7k bqt of kinetic friction between the puck and the ice?

  During the investigation of a traffic accidenta( 7asto- v6fi1x)et( ja 7nrn, 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 conditijt no)vfa7e aian-( s71tx6r(ons. Estimate the speed of the car when the brakes were applied.

  Two boxes of masses m and 3m are stacked. (See Fig. 4-6.) 9*q1 q lbg( lkxk*+rqfjv;qz)The surface between the more massive box and the horizontal v+qf*qljg (lqb; kqz*rk91 x)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 static friction force on the less massive box?

  Two boxes of masses m and 3m are stacked. (See Fig. 4-6.) The surface betmcar7d.1jtj 1m: lii7ween the more massive box and the horizontal surface is smooth ajmj imt: .i7d1ra7 1clnd 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 the boxes?

  An object is on a frictionless inclined plane. The plwfovye) j6 5)g kvt20l xy3qh.ane is inclined at an angle ofy qth0.vvogf)3 y ke wj62lx5) $30^{\circ}$ with the horizontal. What is the object's acceleration?

  A 10-kg mass slides down a flat hill that makes an angle 2j s4mm *hvub5of $10^{\circ}$ with the horizontal. If friction is negligible, what is the resultant force on the sled?

  A mass is placed on a smooth incl regcn(++s,ym m(8q xgined 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 plane tilted at an a,h 08j;+ru thofpdo9 vngle 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 directml)t0 /ve d4y1r,cc7* z)kpjytbvk : yly down an inclined plane, at a constant velocity of 4yt0ct7 y 1 k:*lbcvv kedp)mz,ry/j )6.0 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 dowcn ,jr2+u-xn an 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 rougp/0anz4z cdnt/qq ,6wh $37^{\circ}$ 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 surface. The cagf.(ur4r oyfu5j)hbzaa 4e)0ble attached to the log (hrr.j4b4fgu a uaefyz))o0 5makes 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 incline))g3b oagt xn-d plane tilted at an angle-3nob) ga)gxt 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. The angle of incline is gra.es70hd hew4qdually increased 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 plane4h 0h .eseqwd7?