Which of Newton's laws best explains why motorists should buckl:z,lxlqs e6fiieghe f6y((30 e-up?

  When you sit on a cha(8oi5p0cl h.d b+u knpir, the resultant force on you is

  In the absence of an hvo+rdann) -xyq 70:yexternal force, a moving object will

  When the rocket engines on the starship NO-PAIN-NO-GAIN are sudde t q) beo57lf2vnccl0d .mxv69nly turned off, while traveling in empty space,mqc f).tvc0b75 69elvdn lxo2 the starship will

  A rocket moves through empty space f)b qh5,q5 kuxj): oswhn hbm12(y8 nfin a straight line with constant speed. It is far from the gravitational effect of any star or planet. Under these conditions, the force that mus,)5nn(om w5s qq 1 )8kf:hyxhjbf b2uht be applied to the rocket in order to sustain its motion is

  You are standing in a moving bus, facing ,bqj/ ka: e0m s*ygn0aforward, and you suddenly fall forward. You cankg e/qysj:,m b0*n0aa imply from this that the bus's

  You are standing in a movi-aoslj*0s m,m7dlt yq + bkq+a9o1 8ilng bus, facing forward, and you suddenly fall forward as the bus comes to an immediate stop. What qm0y+9+oaoblmi 1d*ql l,ks8a-7t sjforce caused you to fall forward?

  A constant net force acts on an object. Describe the tb:+jyl 3 zdy9motion of the object.

  The acceleration of an object is inversely proportixp4(l0kfh.1ujsdp o ;onal to

  A net force F accelerates a mass m with an acceleratio d6brmm7x *o*-ocxlw9f w( ux2n a. If the same net force ix2xc**ul9r- mww f obdx(67oms applied to mass 2m, then the acceleration will be

  A net force F acts on a mass m and produces an acceleration a. What acceler7*.o fqwi5 gyuation results iyf ow5.g u7*iqf a net force 2F acts on mass 4m?

  If you blow up a balloon, and then release it, the balloov4q3m fdcmn 01n will fly away. This is an illust3dnqc04 v1 mmfration of

  Two cars collide head-on. At every moment duri9y o5ypeb0o a*ng 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 a *pyo5e9yb0o first. This is an example of

  If you exert a force F on an object, the force which the object exerts on you+nc5ikwt .ps7 will75kc+wt .p isn

  Action-reaction forces t kv6y0x ul/my4ue/hqpj7*: y-m eku pq(j35e

  Action-reaction forces arlmn f / gmlvv6x umd0zm/1r+6v8 ek/b*e

  A 20-ton truck collides with a 1500-lb car as tx72/7v nktsnd causes a lot of damage to the car. Since a lot of damage is done on the carkstx72/ s7n vt

  An object of mass m sits on a flat table. The Eart- wzo,fte x/om1 v11ylh pulls on this object with force mg, which we will call the action force. Whaf 1toyx e 1wv,1/m-zlot is the reaction force?

  A child's toy is susfs0(qpu 2x3x:g.imfwy 2yi/, :aaz knpended from the 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 "action force," what is the "2qx3kmwn :./:ufig0,f yisyz(x2a a preaction force"?

  Your bat hits the ball pitched to you with a 15 wv0 (;1kl fto7m1 3aungx1yyn00-N instantaneous force. The ball hits the bat wifo0; ty( vanmx1yu wknl3g7 11th an instantaneous force, whose magnitude is

State Newton's three );wecm :z 4py ma/gz,olaws.

  Mass and weight

  The acceleration due to gravity is lower on ta(m isu)6x )4fzd qqr3he Moon than on Earth. Which of the following is true about the mass4mq u())xd6ifas3 qrz and weight of an astronaut on the Moon's surface, compared to Earth?

  An example of a force which acts at a distaago2gwyqu n1en w.*n71): l wznce is

  Who has a greater weight to mass ratio, a person weighing 400 N or a persh0/;b li0q3,cdjorhy gt k7 f9on weighing 60ftc30, y0;bk io/jhqr9gdh 7 l0 N?

  A stone is thrown straight up. At the top of its path, ez( xe3xwq5:4hw1 ujlthe net force acting on itxjwezqxh(3u l541we : is

  A 20-N weight and a 5.0-N weighthloi2 b8tm *9d are dropped simultaneously from the same height. Ignore air resi obitd 29m8l*hstance. Compare their accelerations.

  A brick and a feather fal 4.atsqx)be-wl to the earth at their respective terminal velocities. Which object experiences the greater force of air q-s) 4abt.wexfriction?

  An object of mass m is hanging by a str dikn8w4: 5q6i3qulqg ts17guo(:ueying from the ceiling of an elevator. The elevatoi uig8o6l3yk q 5q1uqt:n(7:4w dsu ger is moving up at constant speed. What is the tension in the string?

  An object of mass m is hanging by a string from tkdp 1x 1;;)mraddx(k the ceiling of an elevator. The elevator is moving upward, but slo xkdrp;mx;1k a)1t (ddwing down. What is the tension in the string?

  The force that keeps you from sliding on an - r3b(q .,cg rl(cxdpticy sidewalk is

  It's more difficult to start moving a heavy carton from rest t5w8cr9tu*n k3 c+ yel+ste*nchan it is to keep pushing it with constant velor9s8c * 5*n+etntc3l+cuy wek city, because

  A horizontal force accelerates a box from rest acr.tnyj*.h -sna oss a horizontal surface (friction is present) at a constant rate. The experiment is repeated, and all conditions remain that-.s* hnyj n.e same with the exception that the horizontal force is doubled. What happens to the box's acceleration?

  A packing crate slides down an inclineigt3-.lm-ub gd ramp at constant velocity. Thus we can dg-ibu gm3-l.teduce that

  A block of mass M slides down a frictionless plane inclined at an angle q with8 tt6z67 yemjg4xo bl1 the horizontal. The normal reaction force exerted by the plane on tj6 8 tteb641zmygo7lxhe block is

  A block of mass M slides down a fa 5qlke0 q+w,erictionless plane inclined at an angle q with the horizq,e5aelq +k 0wontal. The normal reaction force exerted by the plane on the block is directed

  A block of mass M slides down a frict p92a:d 9fadjy/8 -iypp bmlg(ionless plane inclined at an angle q with the horizontal. The gravitational force is9b-pf (8g/dm2y:iya9p jlapd directed

  Two toy cars (16 kg and 2.0 kg) are released simultaneously on an inclined plaszmfo ts):dfx 132l ;hne that makes an angle of 30e with the horizontal. Make a statement which best describes 1)3:;xsfo2lfdsmz httheir acceleration after being released.

  An object sits on a frictionless surface. A 16-N force is,czft3 c5qk , n-4ur0emnleq( applied to the object, and it acce qn0uc4fe,3, rczmenk-(l5 tqlerates at $2.0 \; m/s^2$. What is the mass of the object?

  A sports car of mass 1000 kg can accelerate from rest to 27 m/j sb, h2htepvnj;g b;w*/3 eu0s in 7.0 s. What is the average forward force onejhvjpn,/0 *;es2 bb wugth ;3 the car?

  Starting from rest, a 4.0-kg bod8uxw7n -ao ;fc c2jc1ky reaches a speed of 8.0 m/s in 2.0 s. What is the net forc 21c ucc;7fkn-ojw8xa e acting on the body?

  An antitank weapon fircg;copv52w d y5c-) bbes a 3.00-kg rocket which acquires a speed of 50.0 m/s after travedvb cyo5bg 2cw-p5);cling
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-kgm1e2np l0mim/4y zb 3* eokm ,xyvrt32 mass from restnrem4tolmi,b*23/pv0x3e y kmzym 12 ,

  What is the mass of a person w h xr(py9c j;rwf9i;8uogzv;8zr,m7 cho weighs 110 lb?

  What is the mass of an object that weighs 250 N on the surfacemhp : d-xr c1xc mq7lzpy 68n(9yk7r:g of the Earth where the a-xpm:zcykh9q g rm6x:d7pc1ry78 l n (cceleration due to gravity is $9.80 \; m/s^2$?

  An object has a massx 03dnsvnsvof ;8 -gpq1 )qm ca*uqn;0 of 60 kg on the Earth. What is the mass of the object on the surface of the Moon 3vq*; 0;ngm sv unqn1ad)pc 80oq-fsx 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 wew+qpm azc9u(4ighs 40 N on the Moon. The Moon's gravity is one sixth of Earth's. Com+ (qzwp4 cmua9pare the masses of the objects.

  Sue and Sean are having a tug-of-war b3zx8ce85.*gqayr 6k xnrnv q*y pulling on opposite ends of a 5.0-kg rope. Sue pulls with a 15-N force. What is Sean's force if the rope accelerates toward Sue aax rec.x 68 nrz qgk3vq5*8n*yt $2.0 \; m/s^2$?

  A stack of books rests on a level frictionless surface. A force F acts on hxnx01o1n-pp the sta0o-h p1np x1xnck, and 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 stak k84he 3 61+mnfcrslq;; tn+qmdhme 1nds on a scale in an elevator. What will the scale be reading when the elevnfme+std h364rmklh ;1; m1c+ ekq8qn ator is accelerating downward at $4.00 \; m/s^2$?

  A person on a scale rides in an elevator.iw-l xc,u 81tl If the mass of the person is 60.0 kg and the elevator accelerates downward with an acceleration of l-u,wtcil1x 8 $4.90 \; m/s^2$, what is the reading on the scale?

  A person on a scale rv/ qa)bkx7sk+ +ri;yiides in an elevator. If the mass of the person is 60.0 kg and the elevator accelerates a; )sk+iiqy7 vrkxb+/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 masrd g sc8(x,.j8-jk4 kgo; jptgs. One force has a magnitude of 8.0 N and is directed due north. The second forcegj-jk p48c ,gtrk; xs(8o dj.g 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 flatbed of a tr3m:2tff;ucdguvb /i y -03 yrruck. It is held in place by metal brackets that can exert a maximum horizontal force of 9000 N3tcimf2/:ru3 ;yuvd0 rf -ybg. 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 held ik 2oj:r fy1dpz+vgrwojg:;*- n 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 o+ :rw1vgkp;* yrjdgzo: -2jfminimum stopping time if the load is not to slide forward into the cab?

  In the Atwood machine shown in Fig. 4-1, if M = 0.60 kg and t kts bh5w bo:9*14haum = 0.40 kg, what is the magnitude of 9u h:s41btwbaho 5t*k the acceleration 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.pbxtx(ozn7t. xfs-u+k+)2 i k40 kg, what is the tension in the string? (Ignore friction and the mass ook-p+ nubistzx)f2x7 (k xt.+f the pulley.)

  A student pulls a box of 9c w8 v qds;jh1dpt92bxl4 fp .erv6(rbooks on a smooth horizontal floor with a force of 100 N in a direction c(r9br pv.1s;w82edxhtq f 4l6j9vd p 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 horizontaz;seeatam( 8(y1/tif, m pox-l floor with a force of 100 N in a direction of 37.0e above the horizontal. If (;m asz1ef ,oi-mxa( t/py8etthe mass of the box and the books is 40.0 kg, what is the normal force on the box?

  A traffic light of weighr2ndvs6g+b v :t 100 N is supported by two ropes as shown in Fig. 4-2. What are the tenrg2b:d v6v+s nsions in the ropes?

  In Fig. 4-2, if the tensions in the ropes are 50 N, what is the mass obr6cthbh 915zf the traffictb bh 915r6chz light?

  Two boxes of masses m and 2m are in c 0xmgm t-i6cdhbd639uontact with each other on a frictionless surface. (See Fig. 4-3.) What is the accelerationd hb-m0mid3tu c xg696 of the more massive box?

  Two boxes of masses m and 2m are in contact with each other zlu3ke4 gs nd+53otn/on a frictionless surface. l3knnzs/4 35g uedo+t (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 Ff zjq41;fk 9xm+;qrwtig. 4-4.) If the forward force o qt;q41 mfkw+xzrf;j9 n the more massive box is F, what is the tension in the connecting rope?

  Two boxes of masses nu3ul k h3b)q)1z7,parnrw8wm and 2m are connected by a rope. (See Fig. 4-4.) If the forward force on the more massive box is F, what is the acceleration of thea3lw z)) bnh1nkr,ur7u3q8 wp less massive box?

Two boxes are connected by a cord running of(ow p*ce ,h-uver a pulley as shown in Fig. 4-5. Box I of ma*efpo w-,(hucss
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 kiz(lf;n 0rcrxg4 7mqd ;netic frictions between a 3.0-kg box and a desk are 0;(04mn d cgrxlrz;7qf.40 and 0.30, respectively. 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 for plastic on wood are 0.50zb3:vdlw+1 d 2wov fe6 and 0l2wdd ve1+b:6vf3wzo.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 +x directi27 ku a /o69/,+rlpg4i9ynu raeek/i bpk;xaf on. It slows and comes to a stop with a /kxny uap2k /497,9/;ui algrrfik6a o pbe+econstant 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 fs)(b7 rp sqp ti (r*rk ftw(p5/9s8umrorce. A 3.0-N friction for(*kpqr7fp r/w(ssm)rr t 95u8 i(btpsce retards the motion. What is the acceleration of the object?

  A horizontal force of 5.0 N accelerates a 4.0-kg mass, from rest, at a rate raf,h tn)pprv/.thv m**ly- * of $0.50 \; m/s^2$ in the positive direction. What friction force acts on the mass?

  During a hockey game, a puck is give.h- njg-.,m *snea7x k :rovgmnk+f h9n an initial speed of 10 m/s. It slides 50 m on the ice before it stops. What is the coefficient ogm:. xkmnh+nr,v j9*k7egnhfo -sa - .f kinetic friction between the puck and the ice?

  During the investigation of a traffic accidentxz09ot / siu9y, police find skid marks 90.0 m long. They determine the coefficient of fri/ ui0 xztsy9o9ction 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 sta gk04pod0d. lf6kqan1cked. (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 f0 0ondglaqdp6kk1.4 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 sur8s3:8xv. . b xxdvgauiface between the more massive box and the horizontal surface is smooth and the surface between the boxes is rough. If the vxs3diu 8.vxax :g8.b 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 frict 9crcrq/1g0 u :)wvidfionless inclined plane. The plane is inclined at an angle ofirwcd0g9)u fq/ 1cr:v $30^{\circ}$ with the horizontal. What is the object's acceleration?

  A 10-kg mass slides down a flat hill that wx yp0r7)ayrd vifu8 qh1+6z.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 eobo+nrqec8 + +/g+mg with 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 tilte*9wlja cd;63rzrj4z nd at an 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 14: rz kkbtuu)directly down an inclined plane, at a constant velocity of 6.0 m/ krz)4bu:ku1 ts.
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 roucepc t-y/9 ba2l33 jrzgh $37^{\circ}$ inclined plane where the coefficient of kinetic friction is 0.20. What is the acceleration of the object?

  An object with a mass m sl7b(nak 7 9gxnwides 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 weicqqb6tg4sh/xc ) (ms8ghing 500 N along a rough surface. The cable attached to the log mc ms)h(4tx/q sc8bqg 6akes 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 b0 wrrayj;i7-at an anglejwr7br 0yi-a ; 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 inclined plaqmqqzem 30q ,i) 4ip: 5 ddny,wf8*:(kixylbkne. The angle of incline is gradually increased until the object begins to slide. The angle at which this occurs is q. What is the coeffic :iy:qim, n d)m 0 xzwp 3qb8q*,(ki4f5leqydkient of static friction between the object and the plane?