Which of Newton's laws best explains why motorists should buckle-up?t),3ysat(-wfz b r f2u

  When you sit on a chair, the result5,rzn-ohh 2y bant force on you is

  In the absence of an external force, a moving object o.4iexkfrj(16u./e ax bteo0 c rs;(s will

  When the rocket engines on the starship NO-PAIN-NO-GAIN are izgc//:y v ues wl43(nsuddenly turned off, while traveling in empty space, the starship w (:4 eyz/ugl/sv w3nicill

  A rocket moves through empty space in a straight line withhgfq6pa*o(g4b. (ml )flv 7c7f pibk * constant speed. It is far from the gravitational effect of any star or planet. Under these conditions, thel f(gi.bo6g fv( kqcphb4 7fl)a*p 7*m force that must be applied to the rocket in order to sustain its motion is

  You are standing in a moving bus, facing forward, and you suddenly fallyfn1sy1k,uv ( *lly;o forward. You can imply from tl f;(1onklu*ysv ,1yy his that the bus's

  You are standing in a movi +ra0cf3 52 vflrarmf6ng bus, facing forward, and you suddenly fall forward as the bus comes to an immediate r3aral+ 6 50vcrffmf2stop. What force caused you to fall forward?

  A constant net force acts on an object. Descri xya7nk2 f5d0ebe the motion of the object.

  The acceleration of an objecte p++(xrd:w crq/dkdl*igi05 is inversely proportional to

  A net force F accelerates a mass m with an accecivl(2lnx( t )we 7zx;leration a. If the same net force is applied to mass;l zvtix (wxl(7) cn2e 2m, then the acceleration will be

  A net force F acts on a mass m and produces an acceleration a. What accelerati .swlw9mz 9z;lon results if a net 9w.zm szlw9l; force 2F acts on mass 4m?

  If you blow up a balloon, and then release it, the balloon wi2 afmnq1h/j ; -erozd9ll fly away. This is an illustratihendja- f /mo qz9;21ron of

  Two cars collide head-on. At every moment during the coll)xgw+ 7g6ynzsision, the magnitude of the force the first car exerts on the second is exactlsgz76x+ n)gwy y 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 fo5s7sv 59 zlckorce which the object exerts on you wi os5v9s7 zcl5kll

  Action-reaction forcesxsyzb*82zpu+, q 3lkh

  Action-reaction force33hg )j2 lfqvbs are

  A 20-ton truck collides with a 1500-lb car and causes a lot of damage to gg,ndx0-nu c5+y tip ov 7dy;3the cary+ng73i5dt c0y vdgxp, u-;no. Since a lot of damage is done on the car

  An object of mass m sits on a flat table. The Earth purm0kvth2+hm -v dd9aya+g5h 8lls on this object with force mg, which we will call the action force. What is th d05mha-yrhd2va mg+tkv+8h9 e reaction force?

  A child's toy is suspended from thello6n.0x..ffu pu 9k o 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 "actio ffk 9p olu6n..ulx0.on force," what is the "reaction force"?

  Your bat hits the ball pitched to you with a 1500-N instadhjaa zs es )7y,fjh+;h/i9kb0 +7yut ntaneous force. The ball hits the bat with an instantaneous force,ha+ a7 z/kh s7; st+f0)yjuy ,hbjid9e whose magnitude is

State Newton's three larqz8 pa55xmi,x,l2t nq4: pl bws.

  Mass and weight

  The acceleration due to gravity is lower on the Moon tha .kya/*n* p c/wis;rwtzcu9+ an on Earth. Which of the following is true aboutkcw*.ztnw /ir+/ ucaap;sy *9 the mass and weight of an astronaut on the Moon's surface, compared to Earth?

  An example of a force which acts eh kkyuwdi7(,5q*xm; at a distance is

  Who has a greater weight to matz,u ow*s3m .x*eja s(ss ratio, a person weighing 400 N or a person weighing 600 N.*xsm3e u tj sw*oa(z,?

  A stone is thrown straight up. At the top of its path, the n x )*lzbt1mb f)eq, ihk16(yvpet force acting on it is1xmfp* th yl1( ,ze6qikv)bb)

  A 20-N weight and a 5.0-N weight are dropped simultaneously *ybw*iq kt -l. 7k/ sm .0azzjaog/*pgfrom the same height. Ignore air resistance. Compare their acceleration0 wl*j7ks*g /mi*t . ./zykpoa- gzbaqs.

  A brick and a feather fall to the earth at their respectiv0 i+cjeaf.m p5e terminal velocities. Which object experiences tme.p c i+a5fj0he greater force of air friction?

  An object of mass m is hanging by a string from fss5 p m/ujbujb 111d6the ceiling of an elevator. The elevator is moving up at consfsub6d 1bm pju51js1 /tant speed. What is the tension in the string?

  An object of mass m is hanging by a string from the ceiling 6:lpofbu ig5 ie9+gt:of an elevator. The elevator is moving upibfp 6:5+ 9oggutiel:ward, but slowing down. What is the tension in the string?

  The force that keeps you fromnzf*gtv3hc 0m q;y08n sliding on an icy sidewalk is

  It's more difficult to start moving a heavy carton from rest thad4o yh 9)f7 i- jei/upnii:fa)**ytgrn it is to keep pushing it w)ioyjn9y*ff7ri/ )tiid*gpu e- 4: ahith constant velocity, because

  A horizontal force acceleratn087z y2 lj7*v.pwewokvx u j.es a box from rest across a horizontal surface (friction is present) at a constant rate. The experiment is repeated, 7 yv8u7. lp2oj 0*jwe v.wkznxand all conditions remain the same with the exception that the horizontal force is doubled. What happens to the box's acceleration?

  A packing crate slidegmus-aq rj**yoi f-syn539 8ds down an inclined ramp at constant velocity. Thus we can deduce t9 **ifqgd y5jnm oy8- u-arss3hat

  A block of mass M slides down a frictionless pk cgray0r7 o91gbo; e2h; z;ujlane inclined at an angle q with the horizontal. The normal reaction force exerted by the plane ooyzerb;0g17 ;r2;jchuag9 ko n the block is

  A block of mass M slides down a frictionless plane inclm*jz:aw 7 7kga 1b3 5sw7qvjanined at an angle q with the horizontal. T 57azk1:77gw3q jm*naav wbjs he normal reaction force exerted by the plane on the block is directed

  A block of mass M slides down a frictionless plane inclined at anwxhmu6+e0iw 1v42u sqw ; aisd9fs9+z angle q with the horizontal. The gravitational force i 4wzfw +09xe6;h umssa1d29s+uivwqi s directed

  Two toy cars (16 kg a wcr58is8i;jom/ l*8 fg7m urd- ;wdsrnd 2.0 kg) are released simultaneously on an inclined plane that makes an angle of 3 rgu-;c/mm7r8l5*ois8wfsj i d ;8 dwr0e with 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 torjvtp /6m6 7vi the object, and it acpv7jrtvi/m 66 celerates at $2.0 \; m/s^2$. What is the mass of the object?

  A sports car of mass 1000 kg can accelerak7y5qwr/lm*9 e fcs6 ste from rest to 27 m/s in 7.0 s. What is the average forward force on the wefs*q ck6yrl m/759s car?

  Starting from rest, a 4.0-kg body reaches a speed of 8.0 m/s in 2.0 s. 0k)ykw 7u -1si3yrshh What is the net force actiswi- 3kk7rh )hsyy01ung on the body?

  An antitank weapon firvlsnz1:sqm 53x.g :xk es a 3.00-kg rocket which acquires a speed of 50.0 m/s after t:n k1slxzxgs5v q .3:mraveling
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:go4 y.29.r/2zzesbtbp t miv push a 10-kg mass from restzot b:4tbg. 9zpyes2v2 . mir/,

  What is the mass of a person who9 e jbmt08e;m vig)pz9 weighs 110 lb?

  What is the mass of an object that weighs 250-mmxbqmgcs: xb9r: ( 7 N on the surface of the Earth where the accelerats(bq9xmr gx7 -:mc: mbion due to gravity is $9.80 \; m/s^2$?

  An object has a mass of s;j b)f1xzf8v60 kg on 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 1zvb)s; 8fj xfthat on the Earth?

  Object A weighs 40 N on Earth, and object B weighs 40 N on x3bweb 0b /er-mzvf77the Moon. The Moon's gravity is one sixth of Eaer 3bm -xbwz7efb /07vrth's. Compare the masses of the objects.

  Sue and Sean are having a tug-of-war by pulling on oppositepqh /dzfn5acv1 o(f) 8 ends of a 5.0-kg rope. Sue pulls with a 15-N f zn (hap15vq/8) fofdcorce. What is Sean's force if the rope accelerates toward Sue at $2.0 \; m/s^2$?

  A stack of books rests on enuc ovt0db* gkn/t87zv )7v3a level frictionless surface. A force F acts on the stack, and nt*vd8)3tnc 7vov0/gz euk 7bit 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 aq- quq7u8s/w9 yho,yf n elevator. What will the scale be reading when the elevator is accelerating downward9h ,ysqyq/ u8 -fwouq7 at $4.00 \; m/s^2$?

  A person on a scale rides in an elevator. If tfazahd;d kl;(4f)b r.he mass of the person is 60.0 kg and the elevator accelerates hfr akz;bda)4. ;f(l ddownward 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 7ha hg / msznr 9c+p-eqws(g,5the person is 60.0 kg and the elevator acceleratesgq9smgr- s7 ( ch/an,pewhz5+ 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 magnitudef*c p 3z;tsc/ ,o)y1kocsv 9saoa,qr4 of 8.0 N and is directed due north. The second force tows)o,v;qsoz4 ap,a/r1* sky tccfc 3o9ard the east has a magnitude of 6.0 N. What is the acceleration of the mass?

  An object of mass 6000 kg rests on the flatbed0 w. efu7f:4 qerb6lvi of a truck. It is held in place by u.b 6v: fi47lrefw0e qmetal 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 ln h/rri. pnneq38* x cu4+9zctruck. 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 st.inn4e xuc rzph*c39r+ q 8ln/opping time if the load is not to slide forward into the cab?

  In the Atwood machine shown in Fig. 4-1, if 96 nyd,a7 jdxxM = 0.60 kg and m = 0.40 kg, what is the magnitude of the acceleration of the6xy ,9xn7dadj system? (Ignore friction and the mass of the pulley.)

  In the Atwood machine shown in l-1 :sssgm 1idvjvh ;;Fig. 4-1, if M = 0.60 kg and m = 0.40 kg, what is the tension in the string? (Ignore friction and the mass of the pulley.1- s; :divsm jhsl1vg;)

  A student pulls a box of books on a smoos9dn10 9z lx)g mi6kluth horizontal floor with a force of 100 N in l9g0l znk1m)9us ix6da direction 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 sm i5 85/xbzuxpsooth horizontal floor with a force of 100 N in a direction of 37.0e above the horizbxizx5s 5u p/8ontal. 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 rop2y53psj:oa.)vl u/x vgirx p* es as shown in Fig. 4-2. What are the tensions in the ropes.jvo2*g:yxl5p iax) srpvu/ 3?

  In Fig. 4-2, if the tensions in the ropestlp 8djf pm/1 i;z2 2.u.fhzjj are 50 N, what is the mass of the traffic 1ml/2 8 h fjd.j.fj;2zzitpuplight?

  Two boxes of masses m and 2m are in contact with each oti0fe.*q/+r vd c* whzl7rfo:w 3+pnryher on a frictionless surface. d.c7 nfwrhvw l3+eqi*f:oyr/p* 0rz+(See Fig. 4-3.) What is the acceleration of the more massive box?

  Two boxes of masses m and 2m are in contact with eab3 (e2nnr(iz7c)xn t ; 9s;jt *xhnnvrch other on a frictionless surface. (See Fig. 4-3.) (7t*nnxi3jv z2;n nrh)n xsb; re(t9cWhat 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.) If tcivrs a (0k-8ghhj wf 2n- f3ta9n*4mfhe forward force on the more massive box is F, what isf -gn hv83mr*ha-c4 9k(w2ajfifnts0 the tension in the connecting rope?

  Two boxes of masses m and 2m are connected) ivb8a dkw-am4k sr)7 by a rope. (See Fig. 4-4.) If the forward force on the more massive box is F, what is -i4rvkm7b daak )s) 8wthe acceleration of the less massive box?

Two boxes are connected by a cord running over a pulley as shown in Fig. p/(ygn6zcws ,jyrcp v6p5p,64-5. Box I of ms6p,zv5 n6cpjp,g w py/6r(yc ass
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 andww /bai+yknljf6f- b :0s9c u6 z1*ir i)fgeg. a desk are 0.40 and 0.30, respecrf i1c+.0 wugn)/iebk:*- wia jg6y6zslb9fftively. What is the net force on the box when a 15 N horizontal force is applied to the box?

  The coefficients of static and kinetic frictions for7isz.0o * w ;z,bfxvbg plastic on wood are 0.50 and 0.4 ,;zb. 7gsi0 zwfboxv*0,
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 direction. It slows and 1:ex-tu+kuk : ,jnwhycomes to aj:k :-uy1 nut,kw eh+x stop 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 surface0 pih +0ydx7an)ki i7wdd.; bb is pulled by a 5.0-N force. A 3.0-Ny+iw ai0p7 dbnb)7dk.i; hd0x friction force retards the motion. What is the acceleration of the object?

  A horizontal force of 5tl6njjvw7; hmb2o, /wc9 yg*83p z zlk.0 N accelerates 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 puck is given a x5gic*m,0a3gzs r8hdn initial speed of 10 m/s. It slides 50 m on the ice before it stops. What is the coefficie0a riz 3c,*5dxs ghm8gnt of kinetic friction between the puck and the ice?

  During the investigat4)rkt:0o y amcion 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 roadway to be 0.500 for the prevailing conditions. Estimate the speed of the car when the brakes w rco0tka4:my )ere applied.

  Two boxes of masses m and 3m are stacked. (See Fig. 4-6mempa;01o ne 9.) The surface between the more massive box and the horizontal surface is smooth and the surface between the boxes is rough. If the l e0no9pmea 1;mess 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 arbnf6k,a**s74fqnolw cx;et by20 fe *e 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 massive box does not slide on the more massive box, what ifb0oa xsw fk2bt,c4;7nen**e*6 lqfy s the coefficient of static friction between the boxes?

  An object is on a frictionless inclined plane. The planyv9b(38chp1 (ild6 l(ci embue is inclined at an anglei((6 pbim1983 heccuv dlylb( of $30^{\circ}$ with the horizontal. What is the object's acceleration?

  A 10-kg mass slides down a flat hill that makes +5 isbgc-,d tp6w1hf+vlfs a*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 fwp d9 2-;z2itdv1zcthr7pp1z n0ia 8an 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 z-gr21( sjutub6m5 ikan 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 constant velocity wdphp33ramc,9c/ :js/mcz7nn -q /fv of 6w7mh /,f: /scq93 ja/zdcmnrnp pv-c3.0 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 s(1zct6 qsc(lbiui 7 i0lides 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 dowd r*zz+y:dzttr. r/ta/ sj0 .bn 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. The cablvlrm u 6el8(9-u0okay . uz9wge attached tvlu9u 9mayw(-u86kgr o 0lez.o the log makes 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 rn e iei*7i1,zgest on a rough inclined plane tilted at an angle of ig7e*zi1in e, $33.5^{\circ}$ 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 graduallyplsgbf ;,4b 0m increased until the object begins to slide. The angle at which this oc,fp0ls bg m;b4curs is q. What is the coefficient of static friction between the object and the plane?