Which of Newton's laws best explains why motorists jz6xa5e h- fhp7x8j0fshould buckle-up?

  When you sit on a chair, thesh6lp 8k+ g j/a/ecp;bz(c+ vqh3gv8i resultant force on you is

  In the absence of an external force, a 3hax7g9o .tzumoving object will

  When the rocket engines on the starship NO-PAIN-NO-GAIN are suddenly turned ofd/ uis; pi* 7j5by6e1 wpk bnmjhbe0o *o/g1j7f, while tra1/j7e ni*ejh jpb mib0d1o7 5pw6s ;bu*/ oygkveling in empty space, the starship will

  A rocket moves through empty space in a straight line2nj*b s+5edsy0 t mw1besua7i*4v aq4 with constant speed. It is far from the gravitational effect of any star or planet. Under these conditions, the force that must be app4 *2yab1w4b nq*e 5isus7v +j0estd malied to the rocket in order to sustain its motion is

  You are standing in a moving bus,r fryd)0p4tc 0 facing forward, and you suddenly fall forward. You can imply from this that the byfr00)4crd ptus's

  You are standing in a moving buj q),otfbe0udl i9 o39s, facing forward, and you suddenly fall forward as the bus comes to an q dbo3 99 loj0e)fu,tiimmediate stop. What force caused you to fall forward?

  A constant net force acts on an object. Descrt*pd c t )kq5;j w9y2(uubhqz-ibe the motion of the object.

  The acceleration of an object is inversely proportionalx,n1ih7++s7crfkb im b/.w k w to

  A net force F accelerates a mass m with an acceleration a. Ife9 t(dte7 a5k pse+(kgoyup (9 the same net force is applied to mass 2m, then the accelepeu(kaykt 7 99g5(to+ epd( seration will be

  A net force F acts on a mass m and produces an acceleration a. What acnkl*cv84 : aloh 7-j0tqi+gfq:6lfea celeration results if lj chall:-t 4q0+vofnaqgf86e*:7ki a net force 2F acts on mass 4m?

  If you blow up a balloon, and then release it, the balloon will fly away+. +8meklcr xs+ z.h3sm1qmyz. This is an illustration oes 1c mr ++mz+k3xs.hm.yq8 zlf

  Two cars collide head-on. At every moment yx oh3oty7q) v/kajq8q6 ln;8 :fxxq.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 exerts on the first. This is an examx.)8/lxvoxtn qyqqo h aq:6 yfj;783kple of

  If you exert a force F on an object, the force which the object exertn(*hzl-3lcgt 94uob ts on you will-4z93cu(b hn*ltt olg

  Action-reaction forc ffvg90 wk*l rtp5.ygtu6r+cn*sa y.4es

  Action-reaction forcedv(:qny /b-e 0uxk*s(hn/mrxs are

  A 20-ton truck collides with a 15 izaqml/93hy9 c,s9yv00-lb car and causes a lot of damage to the car. Since a l9z lc,y3yva9qsi9 /hm ot of damage is done on the car

  An object of mass m sits on a fl1n)n3kn 5jpa 8(;ckse2bgsyulnt m 7+ at table. The Earth pulls on this object with force mg, which we will call the action force. What is the reactio31e )a(+bly ;un s8j7 kkp2sn5gm ntcnn force?

  A child's toy is suspended *.ovi y avd)uih- oti*l+), dffrom the ceiling by means of a string. The Earth pulls downward on the toy with ia ),lv do+ )*h*. dtuifioyvi-ts weight force of 8.0 N. If this is the "action force," what is the "reaction force"?

  Your bat hits the ball pitched to you with a 1500-Ne1 5q xh+dbo;f instantaneous force. The ball hits the bat with an instantaneoub; hoq ex1d+f5s force, whose magnitude is

State Newton's three la* 7zbxso :tb6ows.

  Mass and weight

  The acceleration due to gravity is low 2(*kwrr *h;bo8lrvb ter on the Moon than on Earth. Which of the following is true about the mass and whv rbo*tl;(*8k br2 wreight of an astronaut on the Moon's surface, compared to Earth?

  An example of a force which ac f8f36foq2 z if1z3hkrts at a distance is

  Who has a greater wei,kvk rru(o8 d3zl )8kught to mass ratio, a person weighing 400 N or a person weighing 600 N?(r dzu ) vk,8lk3rou8k

  A stone is thrown straigeum7p rfe;u/p 1zo/g;r-0 n lcht up. At the top of its path, the net force acting on it pcu7/e 1/fgm; 0pz ;orun-leris

  A 20-N weight and a 5.0-N weight are dropped simultaneously from the same+56zacnp m3 ci3urp z hij+:u6x mdlrq: f4)*p height. Ignore air resistancphzr 5 f 6: +ulcm*zpadnr:u63qij3c4pi+) xm e. Compare their accelerations.

  A brick and a feather fall to the earth at their respective terminal (;wd/rl6t(( mfbti ka. b,dkjvelocities. Whi.ifb6bkd;r( w(k mj,td/la(t ch object experiences the greater force of air friction?

  An object of mass m is hanging by a string from the ceiling of an elevato,)ussm5sr5dh.p, up*fr s g5sr. The elevator is movin,5mssrsfgspuh55ud* s )p,.r g up at constant speed. What is the tension in the string?

  An object of mass m is hanging by32zh 9uvcw1j u a string from the ceiling of an elevator. The elevator is moving upward, but slowing down. c3z291juu whvWhat is the tension in the string?

  The force that keeps you from sliding on an icy sidewalk : i(7ysj-sb s- ryhg5cis

  It's more difficult to start moving a heavy carton from rest than it is tj /f czq23(arwk e35vy q1gtt7o keep pushing it with constant velocic1aj rt/2v(z5q 7yqg3fe3k wtty, because

  A horizontal force accelerates a box from rest across a horizontal surjbg s-*h98x:d 1q:fg nysc p7:w:ja yoface (friction is present) at a constant rate. The experiment is*-bgswgyp a7: :f:: jc1hynsq x j98od 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 b nym(3 5c6 kivu6tzy ((dl/tqdown an inclined ramp at constant velocity. Thus we can deducelv5imnq / ut k( (y6(b6tdc3yz that

  A block of mass M slides down a fu3b stt)-c0c4w c zyh4rictionless plane inclined at an angle q with the horizontal. The normal reaction force exerted hcstzt3w04b) 4cc -yuby the plane on the block is

  A block of mass M slides down a frictionless plane bh95gw ;tb,foz:u jux/m.n; linclined at an angle q with the horihm5u 9wlxo. ;b bt;,zufnjg/:zontal. The normal reaction force exerted by the plane on the block is directed

  A block of mass M slides down a frictionless plane inclinedrr :+6owt 9hhu, suw:y at an angle q with the horizontal. The graviuh o,h9+ wurywt:sr :6tational force is directed

  Two toy cars (16 kg and 2.0 kg) at*pk-,0yis x1 w gaw:cre released simultaneously on an inclined plane that makes an angle of 30e with the horizontal. Maky-01w :acipw*k xt,gse a statement which best describes their acceleration after being released.

  An object sits on a frictionless surface. s.u: fig d/my4A 16-N force is applied to the object, and it amfsydg:.i 4 /uccelerates at $2.0 \; m/s^2$. What is the mass of the object?

  A sports car of mass 100yipbxul90:vokm 0. rg:mw21 p0 kg can accelerate from rest to 27 m/s in 7.0 s. What is the average forward force on .wm l pg:vm1:b0i9x 0uoyr2kp the car?

  Starting from rest, a 4.0-kg body reaches :fb+)ecei: ue..jjax a speed of 8.0 m/s in 2.0 s. What is the net force acting on the b.:cxj :u+a)ee.jei fbody?

  An antitank weapon fires a 3.00-kg rocket which acquires a speed of 50.0 m/s aade i7aa 2t6t+kp c(bsg,9+im fter trgaped9 +s2 ma+tiicb(,6 7 kataveling
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 to.aubr5vb fb pm*v( -j3z 9f8rhe same force that you push a 10-kg mass from rest-(fv.bf8 rm 539aubprovz b* j,

  What is the mass of a person who8 :grt/gxmt(m weighs 110 lb?

  What is the mass of an object that weighs 250 N on the sur 4o/:3ps2e(w s9ys)bus ;vp4obit 6x 5crqr osface of the Earth where rrt b:2c94b ews3 /q)(sp vsyo o6;xisup 4s5othe acceleration due to gravity is $9.80 \; m/s^2$?

  An object has a mass o94uprhgs0 ud 8f 60 kg on the Earth. What is the mass of the object on the ssuu8r4 ph9 g0durface of the Moon where 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 zvti:.e ir wbp 3tf-1;the Moon. The Moon's gravity is one sixth of Earth's. Compare the masses 3 b.rvzetf1;p:-i iwtof the objects.

  Sue and Sean are having a tug-of-war by pulling on ( (cfc 4wbwl-copposite ends of a 5.0-kg rope. Sue pulls with a 15-N force. What is Sean's foccbf l4 -cww((rce if the rope accelerates toward Sue at $2.0 \; m/s^2$?

  A stack of books rests on a level frictionless surface. p0 xwfc81*bhx A force F acts on the stabx *fchx 0pw81ck, 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 sta0yn6 hzjd1p w,nds on a scale in an elevator. What will the scale be reading when the elevzpyw 10dj n,h6ator is accelerating downward at $4.00 \; m/s^2$?

  A person on a scale rides in an elevator. If the9g7. n ra: uyl 1r35r/bievrjs mass of the person is 60.0 kg and the elevator accelerate3e 19.r r /:as5iynb7rvuljrgs 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 mass of the perw6d1zdrv02h j son is 60.0 kg and the elevator accelerateszr61d2w d jv0h 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 ow6*t) hddt; lz :uj2jtf 8.0 N and is directed due nt j;:6z h*2)dltjdwu torth. The second force toward the east has a magnitude of 6.0 N. What is the acceleration of the mass?

  An object of mass 6000 kg rests, (vy3w.mwij y5lc 4lx 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 truck is traveling 15 m/s, what is the minimum stopping distance if the load is not tjm4wcllwxy5 3(y ,iv.o slide forward into the cab?

  An object of mass 6000 kg rests on the flatbed of a truck. 5 f75k2wowofz 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 not to slide forwar5fo527fo zkww d into the cab?

  In the Atwood machine shown in Fig. ha0f;yfx6 ppvbcr5vli 30 15pun 6;am 4-1, if M = 0.60 kg and m = 0.40 kg, what is the magnia;ruvv ;ppi y5 0axf c31bf6n0mhp56 ltude of the 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, whatkh*,+ucoyipb kx16bt 1y.25rq5 wm bo is the tension in the string? (Ignore friction and the mass of th*1 b,1ky5w.bxc 5t6uroo+qpbyhi 2kme pulley.)

  A student pulls a box of booksep 1g ri76hbvk3tdq,, 1);shc-ecoeq on a smooth horizontal floor with a force of 100 N in a direction o-d 3ovec7s1e 1qeh i,k t,; crbpg6h)qf $37^{\circ}$ 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 forc*z iqs mc.t*-ne 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 ont-z.sm* nic *q the box?

  A traffic light of weight 100 N is supported by two ropes as shown in72* .oq yjpun,ube ;od Fig. 4-2. Wha;oq.dn*y juo7p,b2u et are the tensions in the ropes?

  In Fig. 4-2, if the tensions in the ropes are 50 N, whf l(ro2 i1+b nek5la+jigd 02wat is the mass of the traffic lii b+jl 1g w5rio2fn +al(ed02kght?

  Two boxes of masses m and 2m are )ws z: (lyll gz7wvc3w7lmfyt2im2 .6in contact with each other on a frictionless surface. (Swg 6)ty w:lcm vl. szlz7l72i w2y(fm3ee Fig. 4-3.) What is the acceleration of the more massive box?

  Two boxes of masses m and 2m are in contact with each other on a frictionl0 7uohcn;5ost,s nw2 cess surface. (See Fig. 4-3.) Whathun2,ntocs ;5 70owsc is the net force on the more massive box?

  Two boxes of masses m and 2m are connecty7j co 36 z2ailo/a.q h:t-b) bgoce4lj3 pap-ed 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 ropebao)th/ogppozj -i2be3 4j cy:6- laaq37.cl?

  Two boxes of masses m and 2m are connected by a roz* dgb9 j84 qo2/vddzgpe. (See Fig. 4-4.) If the forward force on thezogq/dgz492*dvd j b8 more massive box is F, what is the acceleration of the less massive box?

Two boxes are connected by a cord av adrh+q9skbp4hh c: 89s9m7j-su6 y running over a pulley as shown in Fig. 4-5. Box h9d-96 cahasj :qvm+4s9bh uyp78k r sI 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 hzg s06(e/vf bo9y b)land kinetic frictions between 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/v )bhe(y0g6 zos9blf box?

  The coefficients of static and kinetic frictions for plastic :+oe18i+ 1dbxdobccdon wood are 0.50 and 0.1o dedc+1d:ibob8 +cx40,
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:ic)b dc+qs4sxr(o1 j level surface in the +x direction. It slows and comes to a stoi4 r(q+1ssjdobc:xc )p 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 pulled by a 5.0-N force. A lf w0(ut:0k gk3.0-N friction force retag0fl0wtuk k:( rds the motion. What is the acceleration of the object?

  A horizontal force of 5.0 N accelerates a 4.0-kg mass, 2n p7w av+f)phfrom 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 speedo( .bjjztv 9tpt.3(0er+/hah kg1d lqjt5 1iy of 10 m/s. It slides 50 m on the ice befo1ht jot iqb1kjt5zge0pt y3dl /( .j+vr9h .a(re it stops. What is the coefficient of kinetic friction between the puck and the ice?

  During the investigatiok8g66db ngztc5q 4q h*n of a traffic accident, police find skid marks 90.0 m long. They determine the coefficient of friction between the car's tires and the roadwaygq 8c5b66kdn*t 4g qzh 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.) T kud gqzd1l-29*cq u83e0qlpv he 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 massiv2u80pd1c qzglevkq ud39 q*-le box, what is the static friction force on the less massive box?

  Two boxes of masses m and 3m are stacked. (See Fig.w)bqq, + 9-7uplvymh v 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 slipq,h m qwlb+u9-v7vy)de on the more massive box, what is the coefficient of static friction between the boxes?

  An object is on a frictionless inclined plane. The plane is inzehq:y702*ns ljrp( .j9ojsa clined at an angl0rheso .9yn*a2zj j:lj(ps7qe of $30^{\circ}$ with the horizontal. What is the object's acceleration?

  A 10-kg mass slides down a flat hill that makes an a1:2n x zrs.)p,keizwwngle of $10^{\circ}$ with the horizontal. If friction is negligible, what is the resultant force on the sled?

  A mass is placed on a smoot4d( kejvz2m) yta*1 h shz okhwp9h0:cr-a3z:h 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 plane tilted at an anglees,as6m hr;5e;oxeve -h *ueeqwj/0n9b6:sy 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 constant ve+kbpzb5x u., vlocity of 6.0 u . x5kpvbz,b+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 slv 0-v3fzuyhvzkqy;;t+8l; e o ides 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 +f5zup 4b 6f+csq jhnqaqsj.2d3x8e( down a 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 500 N j:*0s.(kuwhprf kl p/ along a rough surface. The cable attached to the log makes an angle of hj 0*/kuwsr: l(.ppkf$30.0^{\circ}$ 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 inc vrn c:7lp,6pxlined plane tilted at an angle c:v,7 xr plpn6of $33.5^{\circ}$ 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 anglyysq 27d /no9ce of incline is gradually increased until the object begins to slidedosyqc 29 y/7n. The angle at which this occurs is q. What is the coefficient of static friction between the object and the plane?