Which of Newton's laws best explains why motorists 5 :bke9ons,opshould buckle-up?

  When you sit on a chair, the resultant force on you 5 yeib*x+:wn js-dd f)is

  In the absence of an external fv8i.dt;jw c, worce, a moving object will

  When the rocket engines on the starship NO-PAIN-NO-GAIN are suddenly tur(cj6,n 4ngehda7e /adned off, while traveling in empty space, a7/6n,e gacen4djh(dthe starship will

  A rocket moves throughwjvp gwjy4u3,glnnz+ qk4e6+x g+t73 empty space in a straight line with constant speed. It is far from the e+zl n4 p76xnuw, gt4yg+3wqgkj+3vjgravitational effect of any star or planet. 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 forward, and you suddenly fall forwaji :o,+i(z 8yslvo k,mrd. You cvk,j(szi m8 o: yl+o,ian imply from this that the bus's

  You are standing in a moving bus,qo 2rp1 ds;+qc facing forward, and you suddenly fall forward as the bus comes to an immediate psr1qq2 ;oc+ dstop. What force caused you to fall forward?

  A constant net force acts on an object. Describe the motion of the o hpa:s0 d+9 ,0ucx5yu i+ acj:enys4imbject.

  The acceleration of an object is inversely proportional to5phehl q71(xh

  A net force F accelerates a mass m with an ac/ -uy+alz :eo 09ocpwwceleration a. If the same net force is applied to mass 2m, then the acceleration w0y-9+ew: uzaoowp lc/ill be

  A net force F acts on a mass;xnyp1jb; q0ig*2 emqs .wn b;.ep n1u m and produces an acceleration a. What acceleration results n.n;q nxgp* bj0uw2eeim1yb ; 1qp.;sif a net force 2F acts on mass 4m?

  If you blow up a balloon,xe 3( p r+*uwn 3)oxlxs(,elsb and then release it, the balloon will fly away. This is an illustratw( lue*o)(,nxrlsx sxpb +e3 3ion of

  Two cars collide head-on. At every moment during the collision, the magni* tf b9bghw,4sev1 w9vtude 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 ihtbsg1v4,e w9 wvf*b9s an example of

  If you exert a force F on an object, thecybn2jjt430* ay6q h l force which the object exerts on you willyy *ja q4b026jh3 nlct

  Action-reaction force)y2h)fq,zis-l9c g bi +j1y ebs

  Action-reaction forces aritb. r so8c::he

  A 20-ton truck collides with a 1500-lb car and casj3*we m90h mduses a lot of damage to the car. Since a lot of 0j9e*mw3 sdh mdamage is done on the car

  An object of mass m sits on a flat table. The Earth pulls oe 9(zpq5iko horx2tn11c*h0mn this object with force mg, which we will call the action force. What is the reaction force?1 mehnkoco0 hi1x52r*t 9z (qp

  A child's toy is suspended from the ceiling 0u tt 2 7nj)o(hpf.r:d*mp0 i3laqitwby means of a string. The Earth pulls downward on the toy with its weigmu.tipt2:w 3d0h 0jao)tln* i(f p7qrht force of 8.0 N. If this is the "action force," what is the "reaction force"?

  Your bat hits the ball pitched to you with a 1500-N instan)r9 1e itpyraeai ubt/2wp pm44 ,,y8ptaneous force. The ball hitsw e 94rrm aiyy,4a2 1bepp)pup8t,it / the bat with an instantaneous force, whose magnitude is

State Newton's three laws3p) 4i7g/aak /3x lxj5logoq d.

  Mass and weight

  The acceleration due to gravity ijha 1f3eqfi wyh/3 /jcy67*jms lower on the Moon than on Earth. Which of the following is trycy17 a6fhj 3mf/eh*qwj ij 3/ue about the mass and weight of an astronaut on the Moon's surface, compared to Earth?

  An example of a force which acts at a distance i,hyl (y;c7 /muinhq9os

  Who has a greater weight to mass ratio, a peak(4+ zrssfg 5erup0x :yck23rson weighing 400 N or a person weighi 20rseu5 yxr3f+:s( kgapkcz4 ng 600 N?

  A stone is thrown straight up. At the top of its path, the net ynirss: bs *-yf3qx. (w2 vl:eforce acting on it is 3l*y2(bs.f sryxvi:-swe:n q

  A 20-N weight and a 5.0-N weight are dropped simultaneously5)zesri-3nsezuy o, 8 gj h)k7 from the same height. Ignore air-zi) ro)e8sy5nhugej 3k, 7zs resistance. Compare their accelerations.

  A brick and a feather fall to the earth at their re9jm.qj0mjn 8o(i2/y ptvgdj5spective terminal velocities. Which object experiences the greater force of aij8j(5ymv0p.tj go 9dji2mq/n r friction?

  An object of mass m is hanging by a string from the ceiling of an elevatf+ m419g-gr7f yihb11tw3 unktxrwe 2 w:w pb9or. The elevator is moving up at constant speed. What is the tension in the str+f7upr2g1b141y9 brnf9iw ew-wxk3tgh m: wting?

  An object of mass m is hanging by a string from the ceiling of an -vay0 ox9jky)elevator. The elevator is moving upward, but slowing down. Whaoyx)y 9 j0va-kt is the tension in the string?

  The force that keeps you from s ikw/a u4d2,pqje(0eq liding on an icy sidewalk is

  It's more difficult to start moving a heavy carton from restqf(21 g60ge(v 0vohl nhq)vwl than it is to keep pushing it with clwfng)lv(26 q q0o1h( ge0 hvvonstant velocity, because

  A horizontal force accelerates a box from rest across a hori6fq5(fp88r cqkj kxr0 s5-uif tz6ww( zontal surface (friction is present) at a constant rate. The experiment is repeated, awcq 85sqf65uf(rxjfz t0-pr6ik 8k w(nd 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 constant velocity. Thus weihor- dj , j 1.lk7 fo00wzkd6pgbv/g7tlml:, can deduce k/ b7pzlvklg . , lwoj:t0hdm-f76dgo 0,1jirthat

  A block of mass M slides down a frictionless plane inclined at an angle q wir(: vwf7rqh4) : r 9kik,xzhydth the z4rdw,)ykvhrkh :: f xi79q(rhorizontal. The normal reaction force exerted by the plane on the block is

  A block of mass M slides down a frictionless plane inclined at an angle q wid;ycv spbl,;4 zex5m q/9 hyj8th the horizontal. The normal react; 8x9by5vc/j4d;l y sphz, qmeion force exerted by the plane on the block is directed

  A block of mass M sli f mmrp/f/b ew .dsu+dy2-j/ s+nrx9g-6roy-bdes down a frictionless plane inclined at an angle q with the horizontal. The gravif-+om/j/fn-dbrbd essm ryrup6/+-. x yg92 wtational force is directed

  Two toy cars (16 kg and 2.0 kg) are released simultaneo7yi 1 vm/m*f37bwhpzrim 7m-lusly on an inclined plane that makes an angle of 30e with the horizontal. Make a statement which best describes their acceleration after being rel7-13rifv*mhy mp zlw7i b/ m7meased.

  An object sits on a frictionlebqhi71, 8*m /l +vxuwkiwucs :ss surface. A 16-N force is applied to the object, and it acc lvu xm8,wqk*7ui+ /b1hiws:celerates at $2.0m/s^2$. What is the mass of the object?

  A sports car of mass 1000 kg can ab9ufg8a6 c 1lgccelerate from rest to 27 m/s in 7.0 s. What is the averagcuf1l g6 agb98e forward force on the car?

  Starting from rest, a 4.0-kg body reaches a speeia rzr7r(f:tli5) t3u1z3q jnd of 8.0 m/s in 2.0 s. What is ti(13qa3r tni7tl:rzz5 r )uj fhe net force acting on the body?

  An antitank weapon fires a 3.00-kg rocket which acquires adybtk4rvxh p.r/a+3xph8 adfm* ; :e+ speed of 50.0 m/s after travk+y:ha + x/h dpf4p;exar.d8 3tm*rbveling
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 wit6i u.t yarw9t9h the same force that you push a 10-kg mass from rest, ari.69 9wtytu

  What is the mass of a person who weighs 110 lb?xrg(fvlq 7n/n//zt0w -v5 h gr

  What is the mass of an object that weighs 250 N on th qjlr s 4emuq;)wzoo f7v28:;ue surface of the Earth where the acceleration dur)ul;swfuv emoq ;z q j247:o8e to gravity is $9.80m/s^2$?

  An object has a mass of 60 kg on the Earth. What is the 5si;fp-f9i;x 9au lsc mass of the object on the surface of the9lisp 59-u ;fcixa;sf Moon where the acceleration due to gravity is only 1/6 of that on the Earth?

  Object A weighs 40 N on Earth, and q;m v4.tvbk s3 g:sb+w9hj2d robject B weighs 40 N on the Moon. The Moon's gv:k+gst bmv3r w.sj9d; 4qh2bravity is one sixth of Earth's. Compare the masses of the objects.

  Sue and Sean are having a tug-of-war by pulling on opposite ends of a 5.0-kg ro7ey*nb7e v+ewpe. Sue pulls with a 15-N force. Whee+e bvy 7*w7nat is Sean's force if the rope accelerates toward Sue at $2.0m/s^2$?

  A stack of books rests on a level frictionless surface. A forh/;: r0y t ohl-o5zapice F acts on the stacky:ah /5oro zh p-;l0it, and it accelerates at $3.0m/s^2$. A 1.0 kg book is then added to the stack. The same force is applied, and now the stack accelerates at $2.0m/s^2$. What was the mass of the original stack?

  A person of weight 480 N stands on a scale in a(h+1imn2 ndngia3.j dn elevator. What will the scale be reading when the elevator .j21na dmhdn( ii n+g3is accelerating downward at $4.00m/s^2$?

  A person on a scale rides in an elevxfyws d-foovfe 81bjl9 6qv-)g f*a.6ator. If the mass of the person is 60.0 kg and the elevator accelerates downward s v8qojg-flb*961ovweyfx) df6.fa- with an acceleration of $4.90m/s^2$, what is the reading on the scale?

  A person on a scale rides in an elevator. If the mass of the person isk 63cv:pn 5ycqc 3.oni 60.0 kg and the elevator accelerates upward with ancc3 ynv3iqkp5: no.6c acceleration of $4.90m/s^2$, what is the reading on the scale?

  Two horizontal forces act on a 5.0-kg mass. One foss l u z*q9+xc(9jdop7rce has a magnitude of 8.0 N and is directed due north. Th79(lc9+zdqpsxou*j se 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 on the flat,wnv2 7 u7npuybed of a truck. It is held in place b ,7 v2nwu7uynpy 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 is hel te2 s-ns2ixzo+qkk+7kh2bp 0d 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 to2pbk+2s0qk+nz sx -kei 72hload is not to slide forward into the cab?

  In the Atwood machine aqm)sd (sfq1x0tjf7-qr 4 4ln(ci6vi shown in Fig. 4-1, if M = 0.60 kg and m = 0.40 kg, what is the mag(nqsxr jcffadq -lmq v6 i1i(s4t0 7)4nitude of the acceleration of the system? (Ignore friction and the mass of the pulley.)

  In the Atwood machine shown in Fick9xa:eo4t-9/ g bgzbj6 b4 jzg. 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 pul6 zokb: j9zcg9b4- /4j gaexbtley.)

  A student pulls a box of books vimeu/i/4 hwj nj *onx- 5av.b*wyt n0:qo5r 4on a smooth horizontal floor with a force of 100 N4 a* wvn0i5i h:njyvn/oe/4.mu br*to 5-jwqx in a 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 bogx87 xd 3cthh3hq4dpz(r rhyu34dt,4ys- p9 bx of books on a smooth horizontal floor with a force of 100 N in,733x 9dzrhhq(gc pus4hytrtp- 8hx3b4y4 dd 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 the box?

  A traffic light of weight 100 N is suppori+fkqavpz ; 5 f:d43sjqe b4jf,y1l8ited by two ropes as shown in Fig. 4-2. Wh k1ef3;ljvy:b45f ,s+4iza qfp8jq id at are the tensions in the ropes?

  In Fig. 4-2, if the tensions in the ropes are 50 N, whaty wm (np7sw1 3j.g2 cqrsejk8, is the mass of the traffic limrw72y 8 pncewsk3 j,s( q1jg.ght?

  Two boxes of masses m and 2m are in contact with each other on sw9iy/ tb-g- ea frictionless surface. (See Fig. 4-wbeytg/i9 s-- 3.) What is the acceleration of the more massive box?

  Two boxes of masses m and 2m are in contact with eachxhr ;g6x.zt9rt (y6y o other on a frictionless surfaxyr9ttrz y hg.6(ox;6ce. (See Fig. 4-3.) What is the net force on the more massive box?

  Two boxes of masses m and 2m gfwqjh* q lh9 bd4,0u1are connected by a rope. (See Fig. 4-4.) If the forward force on the more massive box is F, what is thwjqqh9, 4uh* lbd01f ge tension in the connecting rope?

  Two boxes of masses m and 2m arft .f/3bwma/lvel 7 4be connected by a rope. (See Fig. 4-4.) If the forward force on the more massive box is F, what is the acceleration oflwe.f m /v/fbta7b 34l the less massive box?

Two boxes are connected by a cord running over a jjqo8el9v /w7 pulley as shown in Fig. 4-5. Box I of me7l wj v98oqj/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 3p(xj w1e t/dfkinetic 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 a 15 N hor(1wxdt 3/f jpeizontal force is applied to the box?

  The coefficients of static and kinetic fmt2 zzd06 jippoveu5/iu0f3 ( rictions for plastic on wood are 0.50 and 0.40 jt3d /f26vu0 zueipzmp 0(5oi,
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 comes7 2hgavebq+q1 to a stop with a constant acceleration of - +2bea1qhg7qv$2.45m/s^2$. What is the coefficient of kinetic friction between the object and the floor?

  A 10-kg box sitting on a horizonta4v11lr ho/cm sl surface is pulled by a 5.0-N force. A 3.0-N friction force retards theovs1h/ cr41ml motion. What is the acceleration of the object?

  A horizontal force of 5.0 N accelerates a 4.0-kg mass, frofet nv,yzcka ()q,awt6ki- -+m rest, at a rate of $0.50m/s^2$ in the positive direction. What friction force acts on the mass?

  During a hockey game, a puck is given an in61c l1zt z:p1exgs0z pl,cbqti.v 67 pitial speed of 10 m/s. It slides 50 m on the ice before it s1csitz6p:z0lxp61 ztv l17cb.e p g,q tops. 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. +an r1 aigp7lai3o;0s0 m long. They determine the coefficient of friction between the car's tires and the roadway to beanp 7 i+l3sog1 i;a0ra 0.500 for the prevailing conditions. Estimate the speed of the car when the brakes were applied.

  Two boxes of masses m and 3m xk*qm 9k gruz42dn 7qx1rap8f2/rto-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 massive box does not slide on the more massive box, what is the static fricnf2 *u k-41xp rr qdazr8t/gkm7o9x2qtion force on the less massive box?

  Two boxes of masses m and 3m are stacked. (See Fig. 4-6.) Tm.w u kbeccqbp6- 1rd)cr/ (+wd)s mg s0h/2wthe surface between the more massive box and the horizontalm0-.2wc rbd)hsp)wd+/c1 erw ts6u/ gm(q cb k 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 y 3b enammfxh:r7(y:1 an anglhbr(:mfyn:ey x1 m7a 3e of ${30}^{\circ }$ with the horizontal. What is the object's acceleration?

  A 10-kg mass slides down a flat hill thanx1*l5 ;npsp7mm,sr jt 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 w6zp(1hufjz( x ith an 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 x6.nq;2qvvw- v9n9urvt xb-r 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 p,i 6fr 1un7qui, 5irkvelocity of 6iu6, n1i fqp,57rkuri .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 mas/s( 7h,nwz8eo qgf(q gs m slides 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 dowylmbzkt; s1 68n 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. (ty;ek;zvxxr*f+zn f:s;n) b The cable attached to the log makes an ang*rfz fz: +(tvyxnsex;;n );kble 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 inclinh l/vq)jlldnar*rzy . 6;9qa 5ed plane tilted at an angle of 9qdl j *y.laz alr qnr/)5v6;h${33.5}^{\circ }$ 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 az b5s;0v;eg qan inclined plane. The angle of incline is gradually increased untilae;gz05sqv; b the object begins to slide. The angle at which this occurs is q. What is the coefficient of static friction between the object and the plane?