Which of Newton's laws best explains why motorists should buckle-u4oen 1g 3p8vjbp?

  When you sit on a chairc8/ gj9muku2 q, the resultant force on you is

  In the absence of an external force, a movimt5/qsk1 ljbo gr,cze, 441 sgng object will

  When the rocket engines on the starship NO-PAIN-NO-GAIN are suddesc-tk y3b :9*/mflgr anly turned off, while traveling in empty space, tt3*ac lg/sy 9r:-kbfm he starship will

  A rocket moves through empty space in a strain+e 5;kz4lqxucm4e-ld5 ;x oxrw.z0a ght line with constant speed. It is far from the gravitational effect of any star or planet. Underuo.n; x;4wk -le4qz50xarcd 5 e+xzml these conditions, the force that must be applied to the rocket in order to sustain its motion is

  You are standing in afbfd 7u -h*+ud moving bus, facing forward, and you suddenly fall forward. You can imply from this that the bu*fhf7ub +dd-us's

  You are standing in a moving bus, facing forward5 kzu*et bo+5z, and you suddenly fall forward as the buze*zb tk5u+5os comes to an immediate stop. What force caused you to fall forward?

  A constant net force acts on an object. Describ/jy o -lmwys7 u.+f3vlv 5xci6e the motion of the object.

  The acceleration of an objectl4p rvg 7gr0c94f2j pt is inversely proportional to

  A net force F accelerates a mass m w0r6aef)frin2 w7yf0j ith an acceleration a. If the same net force is applied to mass 2yf nj0fef7 r60wi ar)2m, then the acceleration will be

  A net force F acts on a mass m and produces an accvsa3p:kj vwlbe+8 uh st7ena )lr *552eleration a. What acceleration results if a net force 2F acts onslj +rvaau) 5: t5l2 7wkv8ehebn s3p* mass 4m?

  If you blow up a balloon, and th( / ;qris8adyken release it, the balloon will fly away. This isyqs/dr a8 k(i; an illustration of

  Two cars collide head-on. At every moment durinmf9fbus) 7/l,j su f8gg the collision, the magnitude of the force the first/sum ffljs g7ub8),f9 car exerts on the second is exactly equal to the magnitude of the force the second car exerts on the first. This is an example of

  If you exert a force iju5 y3e4q:) xipbb5 zF on an object, the force which the object exerts on you willi y5e)u53 bx 4ibjq:zp

  Action-reaction forces 3otqf*+0 gl-rf xq(cd

  Action-reaction forces arft8lj34au9g x3 ho u5ce

  A 20-ton truck collides with a 1500-lb car and causes a z8j)*te4e,)yvrjy t bz3ki78q3lb k qlot of damage to the car. Since a lot of ej3jzyb ,kv 8)e )qq8*zt iktl4bry37damage is done on the car

  An object of mass m sits on a flat table. The Earth q5yhnus-0+hgh9e 7tdpulls on this object with force mg, which we will call the action force. What is the reaction 5ygh9 s uedq+ nh-7h0tforce?

  A child's toy is suspended m j*be00fqoe9oz( a;xihal3v 3n* c+q from the ceiling by means of a string. The Earth pulls downward on the toy with its weight force of 8.0 N. If this is the "action force," what lqan(e0o+fq* c9jz o*xi3; aeb 3h0 vmis the "reaction force"?

  Your bat hits the ball pitched to you with a 1500-N instantaneoyxwpka8j/2+gp8gz /j px -a7 dus force. The ball hits the bat with aajd7 / ypp-/8 p2gg+a 8wxjxkzn instantaneous force, whose magnitude is

State Newton's threeuhxpwr czd-2njgl v6 o-c*4j; 6.4:as2ndu fv laws.

  Mass and weight

  The acceleration due to gravity is lower on thu/a/my3rld/u ;j1zkf e Moon than on Earth. Which of the following is true about the mass and weight of j3 fl1armkdu/ u/y/; zan astronaut on the Moon's surface, compared to Earth?

  An example of a force which acts at a distance is ;s 8)l/wky*ujayis6sup -r/y taw 8r0ru47 bx

  Who has a greater weight to mass ratio, a person weighing l *oyqtk83u; oc.; jlw400 N or a person weighing 60q*y;wlo ckljo 3u .;t80 N?

  A stone is thrown straight up. At the top of its path, l(vfo:i c-kng05o6kf yvewq . 2pd1,pthe net force acting on 5lfcf2-y0ke nkv61. :p,ivdopqw(o git is

  A 20-N weight and a 5.0-N weight are dropped simultaneouslyl8( naxb 6xmqpz-gb1 oiv44h6 from the same height. Ignore i84mx( hz6b 1na4 glbxqpv-o6air resistance. Compare their accelerations.

  A brick and a feather fall to the earth at their respect gl7 vu ihpb*/ q*f+3fufdae1r;j4nx16w8y ttive terminal velocities. Which object experienjdugieab 46rtf qfhx v3 lwf n;1ty+*87*1/upces the greater force of air friction?

  An object of mass m is hanging by a string from the ceiling of an ele0u+btv: asuos ei6a ohtn(7ki39 +f6uvator. The elevator is moving up at constant speed. What is the tension in the string? b6 ouvfh(eo3ku+9a 7i n60sts:u+ti a

  An object of mass m is hanging by a string from the ceiling of anos d id)6iw) tjdj7q(-+vv,r:uju s(i elevator. The elevator is moving upward, but s)uj(+,u)76 ds j oqjw-: vs diviri(dtlowing down. What is the tension in the string?

  The force that keeps you from sliding on an icys1k d0 uw(gtxbfb z4yw56m;r* sidewalk is

  It's more difficult to start moving a heavy carton from rez-u yt4 divjtvgy 2ql)--2.fest than it is to keep pushing it with constaqj-y) ivu2 ty ftlze4-d-.gv2nt velocity, because

  A horizontal force accelerates a box from rest across a horizontal surfacef7di96m.m pqs (friction is present) at a constant rate. Thd im76s.9mpq fe 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 down an inclined ramp at consta-51+8/ph sakb- zf s ghi9upoxnt velocity. Thus we can -sk ohgxf 8ap+zh5u1 p9i-s /bdeduce that

  A block of mass M slides down a frictiormj cq;vj1u gg0n0x-2nless plane inclined at an angle q with the horizontal. The normal reaction force exerted by the plane on the b-gxj ;0mug 21cqnjv0r lock is

  A block of mass M slidesx n jgr69f:5zs down a frictionless plane inclined at an angle q with the horizontal. The ngz nf:sjr5x69ormal reaction force exerted by the plane on the block is directed

  A block of mass M slidesisr hh4 , -cgqt9r x/ mbw2zcg/++wssr3h 6a8w down a frictionless plane inclined at an angle q with the horizontal. The gravitational force iqwi sgcx,3hghwr- +2 + 9r4trha zc68//mssbws directed

  Two toy cars (16 kg and 2.0 kg) are released simultaneousl.q k2 k.sbpcy)y on an inclined plane that makes an angle of 30e with the horizontal. Make a statement which bepk2s)cq yb .k.st describes their acceleration after being released.

  An object sits on a frictionless surface. A 16-N force v9 3zm7iu ebd-,i(:3v owqnvris applied to the object, and it acce qib- n9v:mo viw7,dveuz (r33lerates 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 7bm9csdukt/td hs/,l h2tt;qgw *7-i2 .0 s. What is the average forward force onk,/ thctbdh m*2gusql;-t/72i s dw t9 the car?

  Starting from rest, a 4.0-kg body reaches a spee7bt5vxeg(b. 21.ywz r n+l1kyh-uxkb d of 8.0 m/s in 2.0 s. What is the net force a-15kbl ub y7xzv r+1t.gy2(xn.eh wbkcting on the body?

  An antitank weapon fire kn(lw+-sdpa c.7eman+x;l:a s a 3.00-kg rocket which acquires a speed of 50.0 m/s after traveli :nmea+l(cs ;pdax+7. wl -nakng
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 mfch j6ibp4k2 :por4tco y ;c.;wzl d,;ass from rest,4;f;;p .w:c 2coc oh ,ld6itjykz r4bp

  What is the mass of a person wholu:uv1lze tw/ ;,acj+ *f;iut weighs 110 lb?

  What is the mass of an object that weighs 250 N onvczts4o(5 u s6 the surface of the Earth where the acceleration due tvcsst( uz64 o5o gravity is $9.80 \; m/s^2$?

  An object has a mass of 60 kg on the Earth. What is the mass of the object v6t o*6x; qzlion the surface of the Moon where the acceleration due to gravity is t6l*vi 6x;oz qonly 1/6 of that on the Earth?

  Object A weighs 40 N on Earth, and object B weighs 40 N on the Moon. The Moo-2 qe kkc1 *j8awof+jln's gravity is one sixth of Earth's. Compare the masses of t-k*2k8 jq ecflj aw+o1he objects.

  Sue and Sean are having a tug-of-war by pulling on oppositey,. u3dyjl-em6y u 8yjn5x6 fr ends of a 5.0-kg rope. Sue pulls with a 15-N force. Whatjreyy- f ,.3mujydln5ux6 6y8 is Sean's force if the rope accelerates toward Sue at $2.0 \; m/s^2$?

  A stack of books rests on a level frinw.aik/tyf , 1n/ o7jmctionless surface. A force F acts on the stw,yj1mk7 n .fo//ti anack, 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 stands on a*a t 00z:*lmtlj*3pqgpsh wo 3 scale in an elevator. What will the scale be reading when the elevator is accetzlhw*jt m0 o:03lap3 qps**glerating downward at $4.00 \; m/s^2$?

  A person on a scale rides in an elevator. If the mass of the personaqzr1k /3mi v6- nox2s is 60.0 kg and the elevator accelerates downward m 3or2qkx i6z-1nv/sawith an acceleration of $4.90 \; m/s^2$, what is the reading on the scale?

  A person on a scale rides in an 8 f:+g+kmyg cex.ju)ielevator. If the mass of the person is 60.0 kg and the elevator accelerates upward with an acceleyc )fg+xk ij8+ug: .emration 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 of 8.0 mu;7;ihe+t b qN and is directed due north. The second force toward the east has a magnitude of 6.0 N. What is the acceleration o7u+itbem;;q h f the mass?

  An object of mass 6000 kg rests on the fw7ksx)r/vrf )w sjnk6xk3n(xw :72 p vlatbed of a truck. It is held in place by metal brackets that can exert a maximum horizontal force of k7v f:)j s)wxnr vn2k k7wx/xsr(63pw 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 z y0sm(xsdpwrs cw-8y.nv/3h :j1j p:flatbed of a truck. It is held in place by metal bracketswh::(dc pxm0/ny s sy8-r w.z s1j3pvj 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 forward into the cab?

  In the Atwood machine shown in Fig. 4-1, if M = 0.60 kle-9 3ywh )xbb8wtxxi8 3iqwq x7qi; :g and m = 0.40 kg, what is the magnitude of thhy9xq ;x3:7-q wlx ww8eiiqt ixb b)38e 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, whaff y2e1 m;x2h89 nbvict is the tension in the string? (Ignore friction an9hve2yxbffi m1cn 8;2d the mass of the pulley.)

  A student pulls a box of books on a smooth horizontal nf 6i+g,pmrdc/tng5k n0oq8 0b5y mjeyn5t) 6floor with a force of 100 N in a direction of 50gdb 5ik nmf 8n6tt5p,ne) 6 yy/ cmqjrg+on0$37^{\circ}$ 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 o66c8 up; ip kof35buc8fyzuc.b h4c (an 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 th. u8cabz63b 5h4 fpo68cfu py;( kiucce box?

  A traffic light of weight 100 N is supportebf1 s s 3owha;93gxt4id by two ropes as shown in Fig. 4-2. What are the tensions in the hxg;s1t4abow9 33i f sropes?

  In Fig. 4-2, if the tensions in the rf)jaf;j pja-5v( s e/ropes are 50 N, what is the mass of the traf(vjefjsr5jp / -); afafic light?

  Two boxes of masses m and 2m are in contactts x1hj2k5 *yr with each other on a frictionless surface. (See hsy2tx5*j1 rk Fig. 4-3.) What is the acceleration of the more massive box?

  Two boxes of masses m and 2m are in contactfy db v , juagua)7+8v7ak9at1 with each other on a frictionless surface. (See Fig. 4-3.) What is the net force on the mg8a)1a9 fbkav+7 yadu ,vt7j uore massive box?

  Two boxes of masses m and 2m are connected by a rope. (See Fig. 4-4.) Ifrqe g2 zk7h)dkask7 i)u c83f2 the forward force on the more massive box is F, what is the tensiok2sk7)icf 7u) rqe gdza83kh2 n in the connecting rope?

  Two boxes of masses m and 2m are connecten*nz i1i(b nl vyzdq5br5 8d37d by a rope. (See Fig. 4-4.) If the forward force on the more massivnzbnv i3 l(8d5zndi7*byrq15 e box is F, what is the acceleration of the less massive box?

Two boxes are connected by a cord running over a pulley acemljb q zx(*2:j48yts shown in Fig. 4-5. Box I of jzc :8lm 2b( xye*qt4jmass
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 stapm+4b;5k:ualqx 3 j4 3: qy;qorvxrlhtic and 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 4y+ r::op ;k5rljuhqalxxqb3; qm3v4a 15 N horizontal force is applied to the box?

  The coefficients of static and kinetic f y4trr-qkeu xdt0 *z-/rictions for plastic on wood are 0.50 and 0.zyrdr0k-4 xqttu-* /e40,
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 the +x direy5ar 0w s x/,ecb1gc i4a.8tcrction. It slows and comes to a stop with a constant accelerat/cir gesw xyaca 8cbt.501r4 ,ion 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 akdp s1n,h-( ef horizontal surface is pulled by a 5.0-N force. A 3.0-N friction force retards t 1fhs-n edpk(,he motion. What is the acceleration of the object?

  A horizontal force of 5.0 N accelerates a 4.0-kg mass, spt)i8a xa(.px der ;7from 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. It sl07wx+a7js.d btz+r pqides 50 m on the ice q0p st7j.bra+dzx +7 wbefore it stops. What is the coefficient of kinetic friction between the puck and the ice?

  During the investigation of a traffic accident, poli:y/ddc9s8o 6r wd1 1j vmzeo)nce 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 thend 9c1sjrdz1:yow /6d)e 8ovm car when the brakes were applied.

  Two boxes of masses m and 3m are stacked. (See Fig. 4-6.) The sy w fivd d*72uvzh cjr5;tq848urface 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 static friction force on the less massi5ftc d84 rh 2*zyvvji7wd;8quve box?

  Two boxes of masses m and 3m are stacked. (See Fig. 4-6.) The s(n7fg1 xwj7tnrtr *7aurface 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 sg*r7jt nnta 77fr 1xw(tatic friction between the boxes?

  An object is on a frictionless inclined plane. The planef,8.fry vazs )vu+:ni is inclined at an angle of z vu:vi+fny)f.,s8ar$30^{\circ}$ with the horizontal. What is the object's acceleration?

  A 10-kg mass slides down a flat hill that makes an angla sr8nzemkg(d );:-bs e 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 en4fk 4 y;7 xtfuk;t+cangle 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 ti9hbz xw5z**c mi*d(l;u vyjf( lted 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 1 bbh( )rlca7cxw69zwinclined plane, at a constant velocity ofwaxb hcl6c)w9(r7b1z 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 - - 8ph6dlggrtslides 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 massqvlk(17v nlb* apqa9 9 m slides 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 along a rough surface t;v6/wdy/dapg4, tqz. The cable attached to the log makes an angle ofz ytagt,pv ;qd/w4/6d $30.0^{\circ}$ 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 tiltk21*znzl xq 6 1e-hfpued at an angle op2* h uk1qflnx6e- 1zzf $33.5^{\circ}$ 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 gratz5l d 9834 gx+jqlgbbdually increased until the object begins to slide. The angle at which this occurs is q. What is the coefficient of static friction qbdx8 ll3+4bjggt5z 9between the object and the plane?