Which of Newton's laws best explains why motorists should buckle-up5rn9u5stk2:z mauyap mg /*cbq7ysl60 :*c kq ?

  When you sit on a chair, the resultant force on you is4z1f i zm/1hvd

  In the absence of an external force, :.6pqfal:nptb 8-7b60fc vlartdf;m a moving object will

  When the rocket engines on the starship NO-PAIN-NO-GAIN are suddenly turn 65ms1 spsmg0zsc7g/ked off, while traveling in empty space, the ss 1mm /k5cg0gpszss67 tarship will

  A rocket moves through empty space in a stratz18ll 2t0z,s xgf mn/ijy9/f-8tmfb ight line with constant speed. It is far from the gravitational effect of any star or platjs/b0x1 tn/fg,8m m z2flft9 -izy8 lnet. Under these 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 forwanjjj,l/1l -dird, and you suddenly fall forward. You can imply from this that jdn,l/j j1 -ilthe bus's

  You are standing in a moving bus, facing forward, an.gqr+3 moqu- r pp61ord you suddenly fall forward as the bus comes to an imme+.op 1mr63q-rg opurqdiate stop. What force caused you to fall forward?

  A constant net force acts on an b-f)jee s50:p .vwgucobject. Describe the motion of the object.

  The acceleration of an object is inversely propx5uka k.o9z3 gortional to

  A net force F accelerates 9o9 )ffdl +d.g88nuohxdf9sy a mass m with an acceleration a. If the same net force is applied to mass 2m, then the acceleration wid o9+ghxs9 8l ydnof9u)ff8d.ll be

  A net force F acts on a mass m and produclh bw 93na8j+ pq.ry)jes an acceleration a. What acceleration results if a net force 2F acts a+9lnh yjbw 3 pqj.r)8on mass 4m?

  If you blow up a balloon, and then release it, the ballapn,uv-wf, l7 b(r+1vbn u,a loon will fly away. This is an illul,f7pnvr v1 , n,aba-+uw(blustration of

  Two cars collide head-on(gx;u1 xcup d6. At every moment 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 exadu pg;x1c(6uxmple of

  If you exert a force F on an object, the force which them h jn(n3aq0u5 object exerts on you will0 5qmhanju n(3

  Action-reaction forcesgg . *-rx0/rie. lm jiqx*i0cmj p92vz

  Action-reaction forcenmsg/;ew :/5 vmfc jj3s are

  A 20-ton truck collides with a 1500-lb car andv1:re ; d y7fz:2nqhgy causes a lot of damage to the car. Since a lot of damage is z:g;q1hfn yyedv 2r7: done on the car

  An object of mass m sitspy0 (2) +d4qm byrevim oc*v(4ejp8on on a flat table. The Earth pulls on this object with force mg, which we will call the action force. Whaooyp+mmbnr(dve* 8 ei)y 2p04(v4cq j t is the reaction force?

  A child's toy is suspended from the ceiling by means of a strik351e-qbd0 t otk+ g1irfy:jdpo:cr1 ng. The Earth pulls downward on the toy with its weight force of 8.0 N. If this is the "action forirk-e tt03 k pdg1cjr: o5 f+qy:bd1o1ce," what is the "reaction force"?

  Your bat hits the ball pitched to you with a c4gqoukwhxa 49) eqvv1s c(121500-N instantaneous force. The ball hits the bat with an instantaneous force, whose mag9 )uv1 e q gq2c1vxs4hc(kaw4onitude is

State Newton's three4xqygttf1a .c0 (+ y7n)lf qvy laws.

  Mass and weight

  The acceleration due to gravity is lower on the z89gr 5ol: bi:v9yerv Moon than on Earth. Which of the following is true about the mass and weight of an astronaut on the Moon's surface, compared to Eart:r5 ig l9yb:89zovrve h?

  An example of a force whic *u()1blyzx7dhxnh n;;evu 5h h acts at a distance is

  Who has a greater weight to mass ratio, a person weighing 400 N or a person weig+jl8; )ddx6g ce-iv hjhing g8dx clj-vh6jd ;i)+e600 N?

  A stone is thrown straight up. At tb y(1w6+08qu nc gbtgxhe top of its path, the net force acting on it0c16xqbtn +g(y8bw gu is

  A 20-N weight and a 5.0-N o8d,xjxv th;0 r-p+wy weight are dropped simultaneously from the same height. Ignore air resistance. Compare tj r;- x+v08txh,o wydpheir accelerations.

  A brick and a feather fall to the earth at their respectivc it,gj+ 7z4;h*0yw8)psb;o adfvutz e terminal velocities. Which op7fzh os, g ;0w+);4ytidb*zat 8ujvcbject experiences the greater force of air friction?

  An object of mass m is hanging by a string from the ceiling of an elevatdyynyv6;z7 w 6or. The elevator is moving u w6v6y7ynzdy ;p at constant speed. What is the tension in the string?

  An object of mass m is hanging by a string from the ceiling of an34k but9*eg rw elevator. The elevator is moving upward, but slowing down. What is the t ugw9 e4kb3*rtension in the string?

  The force that keeps you from jvi.2hjb.8bln2ftqf):ya; p sliding on an icy sidewalk is

  It's more difficult to startpdtt(btkt ,ym1j3 w:6 moving a heavy carton from rest than it is to keep pushing it with constant m jb(1pwt3,: dkt6ttyvelocity, because

  A horizontal force accelerates a box from rest across a hor**e c 77fkmmogcp r/4zizontal surface (friction /mm4ckr ecf zp7* g7o*is present) at 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 down an inclined ramrcmt9owtt f+ jh:0b jw3c,n; 6p at constant velocity. Thus we can deduce t ;t63 +r chm9:0jbjotww,cnfthat

  A block of mass M slides down a frictionless plane inclined at an angle q with/ 9fol;3ufubk *s-i:zf wf1vo the hozo -: ffiv3;f1bw k9uls/of *urizontal. The normal reaction force exerted by the plane on the block is

  A block of mass M slides down a frictionless plane inlf6ul: mey wx 6xoc.2pr8v/s7clined at an angle q with the horizontal. The normal reaction force exerted by the plane on the block is directedx 26 x:8.7uvwlmp6fyeolr cs/

  A block of mass M slides down a frictionless plane isrql84kxa8mr 4-f/ ntyvy(t:nclined at an angle q with the horizontal. The(k8rltxs8 t 4- m4:nyr/ayf qv gravitational force is directed

  Two toy cars (16 kg and 2.0 kg) are released si0gs tmhrg xd:crx7(- /multaneously on an inclined plane that makes an angle of 30e wcsrt:7dhgg ( 0rx- /xmith the horizontal. Make a statement which best describes their acceleration after being released.

  An object sits on a frictionless surface. A 16-N forlu7 nzkg8wrv2fl: -u(ce is applied to the object, and it au-v :lg(8 u 7zwnkl2frccelerates at $2.0 \; m/s^2$. What is the mass of the object?

  A sports car of mass 1000 kg can accelerate fr)l 9 g1.ib -tnzb;zelsom rest to 27 m/s in 7.0 s. What is the average forward forceilb n;g.b9l1ts-z z)e on the car?

  Starting from rest, a 4.0-kg +cb6sj i9hlq0 body reaches a speed of 8.0 m/s in 2.0 s. What is the net forc9c j b6q+si0hle acting on the body?

  An antitank weapon fires a 3.00-kg rocket which acquires a speed off yr10w7zo* nav ,w)8 nlfsuk5 50.0 m/s after trave5z fn,w8kln)yv 0rw*o7ufs a1 ling
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 pusfeo: :-heuh +o, il4ksh a 10-kg mass from resk :i-,euoe of+:h hsl4t,

  What is the mass of a+cg/p4g6-c0 3ywk-dz ik- fiuyd;lxg person who weighs 110 lb?

  What is the mass of an object that weighs 250 N qh9k(n,7 no zqon the surface of the Earth where the accelq7n kzo,9(hqneration due to gravity is $9.80 \; m/s^2$?

  An object has a mass of 60 kg oq 8cz9yhn4ojd k*z7x6n the Earth. What is the mass of the object on the surface of the Moon where the acceleration due to gravity is only 1/6 of that on the Eaz 4y76dnj9x qckho z*8rth?

  Object A weighs 40 N on 6; s wifo 8i7nqe;uiu3Earth, and object B weighs 40 N on the Moon. The Moon's gravity is one sixth o8suq3o;ui in 7f6wei;f Earth's. Compare the masses of the objects.

  Sue and Sean are having a tug-of-war by pulling on opposite ends of :i8ir6l imdah4zd:8o a 5.0-kg rope. Sue i:irl6z o amd:88di4hpulls with a 15-N force. What is Sean's force 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 w cuwy t-(;f(vacts on the stack, and ictwuw;( f-vy(t 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 an elevator. What wt(,hdwpyi7 f ;ill the scale be reading when the i;fh(y7dpwt , elevator is accelerating downward at $4.00 \; m/s^2$?

  A person on a scale rides in an elevator. If the mass of the izn ekgy,: ;7(vgula6person is 60.0 kg and the elevator accelerates downward 7i(lk ngya: ;,6ug zevwith 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 person is 60.0 k1iy1c:i2q p +p tsrbo;9:tyiug and the elevator accelerates upward with an accelerationp 12ipby+:o 9 sri ;ty1ciut:q of $4.90 \; m/s^2$, what is the reading on the scale?

  Two horizontal forces act on a 5.0-kg map : w:7owi6fxrss. One force has a magnitude of 8.0 N and is directed due north. Thexo:6:wp w7fri 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 43q/zk c9vj2s*it (q xm4i,bscgm*iqon 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 trave jc(z3 ibi kqqs9xc4/iv4s2qmm**,t gling 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 flab 18)xtmlx-44a -nf3bhn xziztbed 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 th)z1ia lfx hz4nt 8m-- 43xnbxbe minimum stopping time if the load is not to slide forward into the cab?

  In the Atwood machine shown ino7jjzmj4 nx,k2;zd m* Fig. 4-1, if M = 0.60 kg and m = 0.40 kg, what is the magnitude of the acceleration of the system? (Ignore friction and the mass of the puljm j 2mz7k;* nz,4xjdoley.)

  In the Atwood machine shown in Fig. 4-1, if M = 0.60 kg and m = 05rmrnkt fsox)r1 x81 5.40 kg, what is the tension in the string? (ot 5mr n8fxk xr)11r5sIgnore friction and the mass of the pulley.)

  A student pulls a box of bookstdqo atk*3 y/( on a smooth horizontal floor with a force of 100 N in a directio/q* a(3dytkto n 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 bov nxp-ri6s 6lvk/)pi 7vk(d *vx of books on 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 *ks (dnkr6v6p-pv 7i xil/vv)and the books is 40.0 kg, what is the normal force on the box?

  A traffic light of weight81 c dxbxxturws l0ul,. tz6 90hc-ex- 100 N is supported by two ropes as shown in Fig. 4-2. What are the tensions in the ropes?x uwctb-8ehx0,l s0xz-.t6lx9cudr 1

  In Fig. 4-2, if the tensions in the ropes are 50 N, what is the mass of *2 u. ddd+wc/rq ksa0sofu6.vthe trafq.6 saur2vd* kd0w+f/o.cs udfic light?

  Two boxes of masses m and 2m are in contact with each other on a frictionless sut)f;p4m +d:axolzh -.2gt jecrface. (See Fig. 4-3.) What is the accelerationdl .tx2thmjf;gc e4)+p oza: - of the more massive box?

  Two boxes of masses m and 2m are in contact with each os68ym3:epq q rther on a frictionless surface. p:q3q e8 srm6y(See Fig. 4-3.) What is the net force on the more massive box?

  Two boxes of masses m and 2m are connected by a rope. (See Fig. 4-4;k+4w zx mfjkbrh93a 3.) If the forward force on the more massive box is F, what is the tension in the connecting ropeb;a jxmz kfk3 +9hw43r?

  Two boxes of masses m and 2m are connected by a rope. (See Fito2yzh,k*hi1ul aa shiu31q7w 5i8k0 g. 4-4.) If the forward force on the more massive biuahl u5wiy2,tk1 38s oi0qkh* h1a 7zox is F, what is the acceleration of the less massive box?

Two boxes are connected by a cord6 2nzdmo1lt1 e running over a pulley as shown in Fig. 4-5. Box I of1zlem1 2od6 nt 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 kinetibpaf c v;2irr-a7iy6(c frictions between a 3.0-kg box and a desk are 0.40 and 0.30, respectively. What is the ne6r(cfii7av2br ;apy -t force on the box when a 15 N horizontal force is applied to the box?

  The coefficients of static and kinetic frictions for plastic on wood are 064l gs l;bh pyh;k7ps8.50 and7 g8l ;lph;kpsbhs64y 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 d-d;3 cng;lwy ho0,i hsurface in the +x direction. It slows and comes to a stop with a d o0;3cd-ghil y w;h,nconstant 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 forcer/j x)ey8m2xk . A 3.0-N friction force reta /)yke8rjx2m xrds the motion. What is the acceleration of the object?

  A horizontal force of 5.0 N acj-5arsn+ y*u- xmhn6etp 60 ftcelerates 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, a puxp fu.+ xkzrns-wc53v6 h (8cick is given an initial speed of 10 m/s. It slides 50 m on the iceik5uc+3wr68 svnxxc. z p (fh- before it stops. What is the coefficient of kinetic friction between the puck and the ice?

  During the investigation of a traffic accident, police find skid marksr)9q0.b s mdtr i,ia:r 90.0 m long. They determine the coefficient of friction between the car's tires and the rm) ir0qrdt.sab:ir, 9 oadway 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.) The surface b drnq9;,2ussyetween the more massive r, 9u sy2n;qdsbox 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 massive box?

  Two boxes of masses m and 3m are stacked. (See Fig. 4-6.) The surface be.cfgo5wf2 5:m8dubzntween 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 static friction between f5f 2nwu. 5bg 8dmc:ozthe boxes?

  An object is on a frictionless inclined planeny un 7hba/j*2ql09 as. The plane is inclined at an angle of lj9qynsa 2nb/a07h*u $30^{\circ}$ with the horizontal. What is the object's acceleration?

  A 10-kg mass slides down a flat hill that mprfasne2.2.jmmk ly6a p5f + ,akes 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 an angle o7)fl;e .m2xnb3-mg q 9 6osnrzob1rkuf $37^{\circ}$ 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 arszvz42ly y6im*:.x lg*t4*wndi/ don 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 inclined plane, at a constantymi xu0waj r(dz(,1p , velocity of 6.j(i,,ya1 r(wz mpdux 00 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 slide+ (s(a;jz q ee./znpghs 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 slo(;edgjhujbgeln8 p24w5 1 d8ides 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 5 okkdtw9swo t6w.c33 800 N along a rough surface. The cable attached to the log makes 8w wsow3o9tdt. c6kk3an 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 tilted0 wh sbm)(rgx5 at an angle ofb 0(hwrs5m )xg $33.5^{\circ}$ 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. Theokz.ltpxs i654de:8jnhs+ ibs 2 n.+y angle of incline is gradually increased until the object begins to slide. The angle at which this occurs is q. Whne.4:ld pjikys+ b5+x. oz6iht ns28sat is the coefficient of static friction between the object and the plane?