Which of Newton's laws best explains why motorists should buckle-up?tpac( o+3vxqk.nca8f9 d v1 x2

  When you sit on a chair, the resulxvtpa;q2 m302ja ( tfytant force on you is

  In the absence of an external force, a moving object wil +fwoou d)xd -3,eqp;xl

  When the rocket engines on the starship NO-PAIN-NO-GAIN are sudz a 0u/lf29wnwdenly turned off, while traveling uwaf/zwl0n 29 in empty space, the starship will

  A rocket moves through empt2c*/( otrw)zy wb),g pqm) yumy space in a straight line with constant speed. It is far from the gravitational effect of any star or planet. Under these conditions, the force that must be applied to the rocket in order to sustainm/ ) w*oz2tuc rqy,gyb(mp w)) its motion is

  You are standing in a moving bus, facing forward, and you suddenly fall for qbqaqszn;s,:sp(;a1 ward. You can imply from this thatq;q;qsba:npaz s,1( s the bus's

  You are standing in a moving bus, facing forward, and yoc1c i (byv1cgex*j u;*u suddenly fall forward as the bus comes to an immediate stop. What fix u11b c*e;cy*v gj(corce caused you to fall forward?

  A constant net force acty eo y2js5a31f,x qf5us on an object. Describe the motion of the object.

  The acceleration of an obj9.s u-y xyc3;o s d3abhcs1py:ect is inversely proportional to

  A net force F accelerates a mass muq 7uc.leqao-*m 9up0 with an acceleration a. If the same net force is applied to mass 2m, then the acc*uqe.op a70lcu9m- u qeleration will be

  A net force F acts on a mvko9e /knb-: hw8 zvj q0ag10fass m and produces an acceleration a. What acceleration results if a net force 2F acts on mass 4m nofv8zbk9j-g w0hvk1q a:e 0/?

  If you blow up a balloon, and then releas v pzgvk( b3bw0(xt+2dop o0hh* z6wg)e it, the balloon will fly away. This is an(x)gwhw d pvbbz*pk3z(06vo 2+0tog h illustration of

  Two cars collide head-on. At every mw 9uchn2r.2tw .oy 9dhxk+5beoment 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 fir.y2cd e.9xkt n h5wu+9who b2rst. This is an example of

  If you exert a force F on an m4 udw 5v1ri5fobject, the force which the object exerts on you willud45rwf1v m 5i

  Action-reaction forcesgb3,yutgd-; t k+;yvm

  Action-reaction forces arehd0c7a u--) won+s t5q+ x0dbursr,v( qedb-x

  A 20-ton truck collides with a 1500-lb car and k .e8dqwx u,+fcauses a lot of damage to the car. Since a lot o,xe w8 qudfk+.f damage is done on the car

  An object of mass m 8h a58f29rls1 5 movu;wys5cbs r i.uksits on a flat table. The Earth pulls on this object with force mg, which we will call the action force. What is the reactiov us f5;mbui8rysw la5h9c 82r51ko s.n force?

  A child's toy is suspended from the ceiling +hb pale4 3vvll- 6/rgby means of a string. The Earth pulls downward on the toy with its weight force of 8.0p/g blav-reh 4llv36+ N. If this is the "action force," what is the "reaction force"?

  Your bat hits the ballze7:0iiy;adsm ,jwa , pitched to you with a 1500-N instantaneous force. The ball hits s0 izwim;dae 7,,:jy athe bat with an instantaneous force, whose magnitude is

State Newton's three lae.w tvw1js 5 w6po dq8jk020up .8ruyuws.

  Mass and weight

  The acceleration due to gravityz gaik :wm;t98w8o,d y 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, compia,kmy8dtwg o:9w;8 z ared to Earth?

  An example of a force w0b, j70+ u(2h r kco;a8oabrvxijffo3 hich acts at a distance is

  Who has a greater weight to mass h1ztqe 05vi0tl, -quiratio, a person weighing 400 N or a person weighing 60vq itz01q h0iu5e t-,l0 N?

  A stone is thrown straight up. At the top of its path, the net force acting 0x6 xf hs(,yqj5d5uptl:i; c aon p5: ulsh ,cxdx5ft60y( jqia; it is

  A 20-N weight and a 5.0-N w9r +ikuux.1kp1yi l s3eight are dropped simultaneously from the same height. Ignore air resistance. Compare their accelerations.riu ku kp.1x3l+yis19

  A brick and a feather fall to the2: qeau pp53u ;. wae5vwf yc(6t7pskq earth at their respective terminal velocities. Which object experience5.ptv3 fup5;wc ap (:2qeua sy qkw7e6s the greater force of air friction?

  An object of mass m is hanging by a string from the ceiling of an elevatorbjqkzof3g theytb4+27 7b g*:. The elevator is moving up at constant speed. What is the h7jg gtyq+ zob324b7*: bf etktension in the string?

  An object of mass m is hanging by a string fro,68ogs7 hvn ogm the ceiling of an elevator. The elevator is moving upward, but slowing dos8oh7 v6n g,gown. What is the tension in the string?

  The force that keeps you from slidingw.e f 6wdaz*(a on an icy sidewalk is

  It's more difficult to start moving a heavy carton from restuxk x+fkelv1 0r*)*i t than it is to keep pusxx+*1lr u t)ie*fkvk0 hing it with constant velocity, because

  A horizontal force accelerates a box from rest a5c6: ym(ijq jwamw+y w:3jh;tc (* mmicross a horizontal surface (friction is present) at a constant rate. The experiment is repeated, and all conditions remain the same with the exception that the horizontal force jm6mw5:tmq 3ymcc hjy:(*i+awi j (;wis doubled. What happens to the box's acceleration?

  A packing crate slides down an inclined ramp at constant velocity. Thus we can 3qb4a 0lseie fju: yvj+*z2-w d3 ylie0+ 4-u qfjes:*awz b2jveduce that

  A block of mass M slides down a frictionless plane incnvpbcz ;pve m-+()vv)lined at an angle q with t -pmzbcvp e;v)(n vv)+he horizontal. The normal reaction force exerted by the plane on the block is

  A block of mass M slides down a 50deqeiifmnk;ywy b0**;va 0fjjs -1frictionless plane inclined at an angle q with the horizontal. The normal reaction force exerted by the plane on theemi 0isqy5fv;; njj *0 fk-0w1 dabey* block is directed

  A block of mass M slides down a frictionless plane inclined at an angle q za -kjl+ 2me)qwith the hork2m+q e-zj )laizontal. The gravitational force is directed

  Two toy cars (16 kg an5f9v.t cgx9a yvk2w m5d 2.0 kg) are released simultaneously on an inclined plane that makes an angle of 30e wf5xy5w.m k29v9vca gt ith 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 applied to the object/3moj8vxd h;w , and it accelerm v/djh8 3wox;ates at $2.0 \; m/s^2$. What is the mass of the object?

  A sports car of mass 1000 kg c -fq0sbjxb n7-an accelerate from rest to 27 m/s in 7.0 s. What is the average forward force on the c 07xq--jbnb fsar?

  Starting from rest, a 4.0h5,0hkwp 1joq-kg body reaches a speed of 8.0 m/s in 2.0 s. What is the net force acting oo,5j0kphh 1q wn the body?

  An antitank weapon fires a 3.00-kg rocket whz0 vsf1qj(e 9lich acquires a speed of 50.0 m/s after travej9 0fezq l(vs1ling
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 from4yaqjgcci -3 kwiiwgf.2k2 ui6d4 --d re3iyu qd ai6c42 ic -w2i.-kkjd4- wgfgst,

  What is the mass of a persoy 79;*d brhbtzn who weighs 110 lb?

  What is the mass of an object that weighs 250 N on srp4r6* y7 x3vf,slh;q0ae kpthe surface of the Earth where the a srp3r4e,x6 ;avlkq7 0hspy*fcceleration due to gravity is $9.80 \; m/s^2$?

  An object has a mass of 60 kg on the Earth. What2..5qz 52bk tkacq ggq is the mass of the object on the surface .t qq.bzgg5ca25 2 kkqof 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 n9)qt/ fcpf4 sN on the Moon. The Moon's gravity is one sixth of Earth's. Cot pf9q fc/)ns4mpare the masses of the objects.

  Sue and Sean are having a tug-of-war by pullinbp rnu 0(wt8y2g on opposite ends of a 5.0-kg rope. Sue pulls with a 15-N force. What is Sean's fon80t( 2w rbypurce if the rope accelerates toward Sue at $2.0 \; m/s^2$?

  A stack of books rests on a level frictionless surface. A force F acts on the *5ggqsk5l6e-xi *dg,d kwmy6 stack, and it acceleratem56 6x y- g*ldw*kkeigs,gdq5s 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 48aw( / ndnu*eryhpo/ e 7yr2i+kf/kj430 N stands on a scale in an elevator. What will the scale be readin/j k* e(4hiur/w+ya 3pnfe/ kdny2or7g when the elevator is accelerating downward at $4.00 \; m/s^2$?

  A person on a scale rides in an elevator. If the mass of7jory,9zl0zomme/ ; 3yysse 0 the person is 60.0 kg and the eleva zrs0 yl9s37yozo my;,/0meejtor 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,it8 ep1u7 td:twm*d:omfk 6q ss of the person is 60.0 kg and the elevator accelerates up7:td k*em wmoq6 tupti1d,8:fward 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 forswaz pvf(+ )o*ce has a magnitude of 8.0 N and is directed due north. The secona)pwf vzso*(+d force toward the east has a magnitude of 6.0 N. What is the acceleration of the mass?

  An object of mass 6000 kg rest,cmo)bbx w 2st7yj9mf 3zz:4d s 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 travm) xj:9zz 7w,ot4m32ybcs f bdeling 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. Itl-rlu)wd+a m s6 .5tdg is held in place by metal brackets that can exert a mamu .dwrg6 s+lt- d5)laximum 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 shownuzx b+1tr zo;pjq(/5d in Fig. 4-1, if M = 0.60 kg and m = 0.40 kg, what is the magnitude of the acceleration of the system? (Ignor ;1xbu+q(rz5jt p od/ze friction and the mass of the pulley.)

  In the Atwood machine shown in Fig. 4-1, if M = 0.60 kg and m = 0.40c40iels sy8 2z kg, what is the tesyzs480 2el cinsion in the string? (Ignore friction and the mass of the pulley.)

  A student pulls a boxmmc:a. 8y d4p08imdv n of books on a smooth horizontal floor with a force of 100 N in a di .cmv8 imap ym8n0:4ddrection 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 of books on a smooth horiz do:nti7 h8dmg,mj7z d3g1.i eontal floor with a force of 100 N in a d jm 87,e.gm:i z3hd71nd todgiirection 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 box?

  A traffic light of weight 100 N is supported by two ropes as show-q(65 voffy1 h74om7m ob arux7e 6fpun in Fig. 4-2. What are the tensions in the ropes hv661ffmpero 77b o47-moq5x fua(uy?

  In Fig. 4-2, if the tensions in the ropes are 50 N, what is th* +4 vki3/e3bor0uc )*y 9 cqrlaxkpbhe mass of the traffic ligp*h3eka+uix/ co9b q0 clk*3rbvry4 )ht?

  Two boxes of masses m and 2m are in contact with each other on a6ig,b+)drhbq frictionless surface. (See Fig. 4-3.) What is the acceleration of the more massib)6 d +rghqib,ve box?

  Two boxes of masses m and 2m are in contact wit7*v: 3ydjvfhex/ zgqy;2b um6h each other on a frictionless surface. 3f6mh/7qyj:z2 vgvxeb;*u yd (See Fig. 4-3.) What is the net force on the more massive box?

  Two boxes of masses m and 2m are connected by 7di0,,ntae yj a rope. (See Fig. 4-4.) If the forward force on the more massive box is F, wh,n,y i 7tej0daat is the tension in the connecting rope?

  Two boxes of masses m and 2m are connected by a rope. (See Fig. 4-4.) Ibq1e)u ab/ub8,v 8b gkf the forward force on the more massive box is F, what is the accelerativ1bg8bka8/ )bequub , on of the less massive box?

Two boxes are connected by a cord yj/ ojw5efq8 gd+k6t1running over a pulley as shown in Fig. 4-5. Box j 6wdgk1+j/fe yq8ot5I 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 and kinetic frictions between a 3.0-kg box and a desk i)j/r* o 4crocare 0.40 and 0.30, respectively. What is the net force on the box when a 15 N4jr*oc rco)/ i horizontal force is applied to the box?

  The coefficients of static and kinetic frictions for plastic on wood6 e+cgy-i (ec khra95d are 0.50 andc aeyh 5rd k-6i(e+gc9 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 the + nqip;8qv,d)ug80 xuqx direction. It slows and comes to a stop with a constant acce 8q;qudqn xu8p) iv,0gleration 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 puvk . cf35 u7tk;xdqx+alled by a 5.0-N force. A 3.0-N friction force retards the xq5+t.c d7 k;ua xkfv3motion. What is the acceleration of the object?

  A horizontal force of 5.0 N accelerates a 4.0-kg mass, fro7xir30av erb ,1plyc/6v gz, vm 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 i8:y-ku xk2d j8f+v r2zi+7z vojrth4is given an initial speed of 10 m/s. It slides 50 m on the ice before it stops. What is the coeffi+xodrz8jf:jrv27+ 2h k ky-8zvui4ti cient of kinetic friction between the puck and the ice?

  During the investigation of a traffic accident, police find skid bgd lhs,83uw/ tf3nb*marks 90.0 m long. They determine the coefficient of friction between the car's tires and the roadway to be 0.500 for thn3bf*d lu,wh38g/s bte prevailing conditions. Estimate the speed of the car when the brakes were applied.

  Two boxes of masses m and 3m+49bbj,qjzkpt ) ea81f,afwi are stacked. (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 mbj)ak4qt ,wej9+8f iz1 ,fpba assive 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 s*qef )x:pvt .j3z;gdz tacked. (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 f .eqx)pzg:t v3*jzd ;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 incline6 qvzc28 y4m4mzadl (j6o e4a uom20okd plane. The plane is inclined at an anglq eoav064mk m 8jc zua 2z(y2molo46d4e of $30^{\circ}$ with the horizontal. What is the object's acceleration?

  A 10-kg mass slides down a flat hillgw ela(*lcff4:4 g3ehs:l *:qjchzs / 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 smooth inclined plane with 3rupcj56b, 4 b*ua 3a b6s eu3cijl.gban 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 ahb h.fa,j ;a(kqs:a,ykp 37kj ngle 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, atn3z4n ,c wc*nj a constant velocity of nzwc * nnj,4c36.0 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 down a nw9fakq)48fy2j/kna. r9 cujrough $37^{\circ}$ inclined plane where the coefficient of kinetic friction is 0.20. What is the acceleration of the object?

  An object with a mass m slidescqq6k )a sd udyv,t/7t iw ,geq18.qi0 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 5w. u /gvtu qpsm+s5-/w00 N along a rough surface. The cable attached to the log makes an angle of smwuvw/5 ptug.s q/-+ $30.0^{\circ}$ 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 incli;r9;m+:abffo llc9jrzou2 : pned plane tilted at an anglecbrjua2omz;r o 9: f +;ll:fp9 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 incl+ 2kste*5 1m)kwwg.cuz-, abnmqv u,qined plane. The angle of incline is gradually increased until the object begins to slide. The angle at which this occurs is q. What is the coefficient of s b1mwc*g +e5atw. n2m )vu-qk uq,z,kstatic friction between the object and the plane?