Which of Newton's laws best explains why motorists sh5q )h(tdmggm/r9hyv ;ould buckle-up?

  When you sit on a chair, the resultant force v1xkz 4x7zr jtuofi-3yn33 :qon you is

  In the absence of an external force, a moving object will*dt ibypo 82;ww8 1aqk

  When the rocket engines on the starship NO-PAIN-NO-GAIN are suddenly turned0cc9lwsvbum0 n+ nc,i01 g8yh off, whin g+0mb0is1wcvhcnc ,l9u 8y 0le traveling in empty space, the starship will

  A rocket moves throughsv9f+rqf8sw +.sz. 8zpymuz; empty 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 appliedzsmv9psr;zs8. y+.8wu+ ffzq to the rocket in order to sustain its motion is

  You are standing in a moving bus, faroj(; dx.(nji4l f 2,9h s/kov v8idmqcing forward, and you suddenly fall forward. You can imply fro/sikqor; l.xv o2fn 9 (j8dm4, (ijdvhm this that the bus's

  You are standing in hk thv 1w(jwqi f/k002w/b:nsa moving bus, facing forward, and you suddenly fall forward as the bus comes to an immediate stop. What force caused you to fa1bhi/0 s hw /wk(kjq2fnvt:w0ll forward?

  A constant net force acts on an object. Descnnqlh . 45/ wlemo74rkribe the motion of the object.

  The acceleration of an object is inversely proportibpi4heab740+ca te 1qonal to

  A net force F accelerates a mass m with an acceleration a. If the jws/o p-. d3:::xr( ddy9f5 u1 dqhn0vr ogzcjsame net force is applied to mass 2m, then the acceleratio95:v /d-chojqf x d3 udzd0pr.nyor(jsw 1:g :n will be

  A net force F acts on a mass m and uhc:a*per) ktij-2px 7lbe .;produces an acceleration a. What acceleration results i2uhir*c klbjpx te); -7.:ea pf a net force 2F acts on mass 4m?

  If you blow up a balloon, and then re;c swecet21iubc*8z7m(f s.-kfd b 6rlease it, the balloon will fly away. This is an ilfr-cm7u c2seet *1bw k;b.(cfsi8z 6dlustration of

  Two cars collide head-on. At every moment during the collision, the magnitude zo8vo9k4-l xm of the force the first car exerts on the second lm -o48o9kzv xis 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 F on an object, the foru16pdc1(2ugj) hq d wwce which the object exerts on you wid6gwdup ) jh(121q uwcll

  Action-reaction forces xu tu8w**n/g7 t-z3qe tb9jdv

  Action-reaction forceqpd g*n29bh -ms are

  A 20-ton truck collides with a 1500-lb car and causes a lot of damague: )x1lgrn2q*n 8es1 uv cvv5e to the car. Since a lot o 8uu1)es gle2n1vrcx*v5 nqv :f damage is done on the car

  An object of mass m sits on oov8/kzin8+ z a flat table. The Earth pulls on this object with force mg, which we will call the an oizz8v 8+ok/ction force. What is the reaction force?

  A child's toy is suspended from the ceiling bylct(:o4zfm z9 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 ic l fo4:9tz(mzs the "reaction force"?

  Your bat hits the ball pitched to you with a r-m0 1rw(n,rm :oqnpd 1500-N instantaneous force. The ball hits the bat with an instantaneous f(mnmr w-0oqr n1 :rp,dorce, whose magnitude is

State Newton's three l(u usnl iew yp 3+e7nw33/(nslaws.

  Mass and weight

  The acceleration due to gravity is lower on the Moo(2a u9h-b3zvlo7- zo cbwwl d8x*)ltbn than on Earth. Which of the following is tru3uz bot*98 -obxh)v-cl w( azd27 bllwe about the mass and weight of an astronaut on the Moon's surface, compared to Earth?

  An example of a force whi7 v.h whz6 (jdfi 0dsja:j+v8tch acts at a distance is

  Who has a greater weight to mass ratio, al*kuw) +gwlfodw) nn+v qn 7yr1 ,7t1c person weighing 400 N or a person weigh*n)rwn fww1 u ynv,gok7dclt)17q+l+ ing 600 N?

  A stone is thrown straight up. At the top of its path, ykwq5zbq) 9y3the net force acting on it zwk) qy y93qb5is

  A 20-N weight and a 5.0-N weight are djur3w 99c r3 kzdoz1qu d7v0f5ropped simultaneously from the same height. Ignordz3z0cu9odj3 krwf 1ruv75 9q e air resistance. Compare their accelerations.

  A brick and a feather fall to the earth at their respective terminal velocitk kc 143q cjuah+vm04gbwlb;.ies. Which ob;1 u4.clv+3q04j kbwc hakg mbject experiences the greater force of air friction?

  An object of mass m is hanging by a string from the ceiling ofptf c5i(( l-4y nz7y5nlrnk;o an elevator. The elevator is moving up at constant speed. What is the tension 5cl k;irl-(no7yft4z 5(n yn pin the string?

  An object of mass m is hanging by a string from the ceiling of an e0n6 qoq0 5-)ry d2jcy12mqa mnl-phwx levator. The elevator is moving upwn06ox wy2yq5pa)r0d1nch q2mq -jlm - ard, but slowing down. What is the tension in the string?

  The force that keeps you from sliding on an icy sidewalk isb6zp6i; o)zpd gzo9i3

  It's more difficult to start moving a heavy carton from rest than w01bye1 jhq7h(cq 5pwit is to keep pushing it with constant vel0j1 h eh15wwp7qc (qybocity, because

  A horizontal force accelerates a box from rest across a mg ls.ag6 4 pxkx+yr2yd,3; tlhorizontal surface (friction is presena .;xx 4pmt3g gr+ksyy ld,62lt) 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 ramp at consawl h7b1 ac9c5rsm 2d5tant velocity. Thus we can deduce acl a 97d 1shr5m5w2cbthat

  A block of mass M slides down a frictionless plane inclined at an angle q with t prlz 66rhsp(+he horizontal. The normal reaction force exerted by the plane on the b6splz 6rr( ph+lock is

  A block of mass M slides down a frictionless plane inclined at an angle q with tw(-mmku e/2xkty6 cq0 he horizo qu(2mw6kky/0e xtc- mntal. The normal reaction force exerted by the plane on the block is directed

  A block of mass M slides down a fri4v n:ao3 zru4epjr:0zctionless plane inclined at an angle q with the horizontal. The gravitational force is directe4:po3evu 0z njr:4zrad

  Two toy cars (16 kg and 2.0 kg) are released simultaneously on an inclined x1 vb2,un cs.q2xtj s9plane that makes an angle of 30e with the horizontal. Make a statement which best describes their accel2ss .x 2b 9nvcujx,1qteration after being released.

  An object sits on a frictionless surface. A 1 yb+;ucxm 518;yj hqnb6-N force is applied to the object, and it acceleratebq 58b x;yy+m1un;j hcs at $2.0 \; m/s^2$. What is the mass of the object?

  A sports car of mass 1000 kg can accend7afgq.ni( kp7 r a) 0wsj9r7lerate from rest to 27 m/s in 7.0 s. What is t 7)7pnnq7kaaw0g9jisf. rrd (he average forward force on the car?

  Starting from rest, a 4.0-kg body reaches a speed of 8.0 m/s in 2.0 s. y+vpr.ih5 :d1l)d pvl8e 7kep What is the net force acting on the +pk.l 175levip: pd)y hve dr8body?

  An antitank weapon fires a 3.00-kg rocket which ac z)7j40y8tk zgr,dsw9 xt4g+ei3woxj quires a speed of 50.0 m/s after jgei9gjwt d73sxxz o8+r, 4zyktw 0)4traveling
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 9ulf p hexl ucv,;;bt):d;co(with the same force that you push a 10-kg mass from re9:o;b uxu)cctpev;;hl(ld f ,st,

  What is the mass of a person who weighs 110 lb,f:sm zxa 6e70igp,-jtwpuo :?

  What is the mass of an objec hn7bh;0g bdy8t that weighs 250 N on the surface of the Earth where the acceleration due td n870;h gbhybo gravity is $9.80 \; m/s^2$?

  An object has a mass odk( hgoel6-y+ f 60 kg on the Earth. What is the mass of the object on the surface of the Moon where the acceleration d(y gh kd-ol+6eue 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 the Moon. The Mohh wg1j aef/ 6jwt8.:von's gravity is one sixth of Earth's. Compare the masses of theht/j68.j1h :wawv feg objects.

  Sue and Sean are having a tug-of-war by pulling on opposite ends of a 5.0-kg rop)+t/c gjq4ybj e. Sue pulls with aq c)+ j4gytbj/ 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 surfaultpui18k /m u7k )me3ce. A force F acts on the stack, um7k)3pu1 l/utkiem 8and 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 l.0g5k,y8 gu gzeaam/on a scale in an elevator. What will the scale be reading ggl8yk/m5u.a gae, z0when the elevator is accelerating downward at $4.00 \; m/s^2$?

  A person on a scale rides in an elevator. If the mass of the person is 60j)eftgg y.h ,7.0 kg and the ejgey gf,th7. )levator 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 mass of the person is 6003mlrg q3qexyf7+gnea49l* e .0 kg and the elevator accelerates upwarf+q3emle4 na9 7 q3g*xegly0rd 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 of 8.0 N am go7o9..t2 a/p fjeepnd is dir9j a7 .tf2popgom/ee. ected due north. 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 rsht hv1 :f+ sq8dot6*insz2.ie7rg034 lzjxoests on the flatbed of a truck. It is held in place by iv6t2o+qgeoh8iszhs.4f 1djl0 :t 7xrs3n z*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 to slide forward into the cab?

  An object of mass 6000 kg rests on the flatbed of a truck. It ic.c9m)i s blzqr,9(t gs 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 t,czlci s.t) (r9qgm9 bo slide forward into the cab?

  In the Atwood machine shown in Fig. 4-1, if M = 0.60 kg and m = 0.ll /-k1,- (cbv(9vq l61mh2it osdji swnuox 940 kg, what is the magnitude of the accekibd- - lsljs62i9o(lu,x/hmwn9 o c1t vv(1 qleration 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, what qt7wijx9jif 3 i+/6qm 5 .ylnndoc ++qis theiiqf t+wcql5q 3+j7d9 jn 6oyn/.mx+ i tension in the string? (Ignore friction and the mass of the pulley.)

  A student pulls a box of books on a smooth ho 3jdl*d7fd wpg/(kx( qrizontal floor with a force of 100 N in a dir l*dq(dp7g 3(kwj fd/xection 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 smooth8*7dayzr 2fc y horizontal floor with a force of 100 N in a direction of 37.0e aryz*yfd87a c2bove 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 shown in 6 jdz6g6vp2 iopg d5v*Fig. 4-2. What are the tensi56ppd gi62o *6vgjdzvons in the ropes?

  In Fig. 4-2, if the tensions ay2)phh.wpzwvhb qh56y:0 :n tv; 3frin the ropes are 50 N, what is the mass of the traffic 6h;r p3z:52y yhft.0 vh :qhv pwabn)wlight?

  Two boxes of masses m and 2m are in contact with each other on a fricti5:qknqgvu j,enkb:aq*0od6* n 7iz f*onless surface. (See Fi j*i*kganq7dbuq znf0n 5:v:e,oq k6*g. 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 a6o 5.5 uks o9xp+wwkvzpshn 41gtj.b4 frictionless surface. (See Fig. 4-3.) What is the net force n 1t4.ww p4op95sxj.ko hk5g sb+vz6uon the more massive box?

  Two boxes of masses m and 2m are connected by s/l40(gpiq /nw ghq( la rope. (See Fig. 4-4.) If the forward force on the more massive(/ gs /lwpgqnl0 4(qih box is F, what is the tension in the connecting rope?

  Two boxes of masses m and 2m are connected (9v/wvw2t hzqzuq:q2e5 +jxfby a rope. (See Fig. 4-4.) If the forward force on the more massive box is F, what is 2j2th9qwq uv+:qvze/(5 wfxzthe acceleration of the less massive box?

Two boxes are connected by a cord running ovfx62 ai//t jarnm,wn82 s7la ner a pulley as shown in Fig. 4-5. Box I o76la, i8xaja/n2s rm/wntn2 ff 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 betwe)v8fbhhs1 nl7 en a 3.0-kg box and a desk are 0.40 and 0.30, respectively. What is thel bv1hf7n)sh8 net force on the box when a 15 N horizontal force is applied to the box?

  The coefficients of static and kinetic frictions 0vdwljpb w k:u: eo u3h,9d2s0for plastic on wood are 0.50 and :do0vj 9 eu3,0s uhd k:lp2bww0.40,
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 +8y,ztn k6k8da x direction. It slows and comes to a stop with a constant accelerationtykz8, 6knda 8 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 3.0z/nuz jy-dz6o+ au 0+l-N friction force retards the motion. What is the accela+ydulzju06 + n oz-/zeration of the object?

  A horizontal force of 5.0 N accelerates a 4.0-kg mass, frogy6;/ cbkymh8 l8vq)*(nbarbm 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 p +sz 6;(wotu9hantaj53kex5slides 50 m on the i95 a h;tzs5j u3pokwtaxn +(e6ce 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 marks 90.0 mk2. 9 v(k irrcode3iw- long. They determine the c d eci 9-rwrk3.ov(ik2oefficient of friction between the car's tires and the roadway 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. rd8pjqr /k0yv(su )+cmxs ;c. 4-6.) The surface between the more mass;xr/)s0+sp q ykcru d.v8cj( mive 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 massive box?

  Two boxes of masses m and 3m are stacked. (d,t+v3hzq )tn : (qh)ebsb fj0)q5ysy See Fig. 4-6.) The surface between the more massive box and thejsqby)n s)d h,q t+)z5b(t hqvy:0f3 e 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 the boxes?

  An object is on a frictionless inclined plane. The plane is inclined at ho tcp6( jwr26an angle ofh66w c(2tproj $30^{\circ}$ with the horizontal. What is the object's acceleration?

  A 10-kg mass slides down a flat hill thatfup bpzuhh)xz9.9, e; 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 an h/v8-bmuk)ea:u: zhqangle 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 angng-.*6kn op 6hnm*5ukp unpw;15e l fqle 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 plan 6sk 5uktiq1+wt* ya3we, at a constant velocity of 6.0 m/s. + kq1as kwtywt*35ui6
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 rh kjip e4;2v/0o8pvxuough $37^{\circ}$ inclined plane where the coefficient of kinetic friction is 0.20. What is the acceleration of the object?

  An object with a mass m schdwnm. c6gz3mfg v9p) x2:lq 2j)6yalides 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 surfa8am k-py+ ik4cynv,4r:6 wxv71ns ovfce. The cable attached to the log mak8vp-o,ai n my+fkk:v 4xcr7 wvy4sn61es 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 inclined plane tilted at an anglea+rch ukdb(;3w qp;nm+ 6 a4ir ofc qm+r;r6wakpnd; +ba3h( 4i u $33.5^{\circ}$ 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 incmu j-tn,1def 2m2jb6 og6 b0rcline is gradually increased until the object begins tmm2jr jct6 2- 6obbu1,d ngf0eo slide. The angle at which this occurs is q. What is the coefficient of static friction between the object and the plane?