Newton’s law of motion - 无忧得胜-网上国际课程 (5edu.win)

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1#

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99.36: What happens to the inertia bi8- 5mwxozk.-+8z,w q zg6teih1rw oof an object when its velocity is doubled?

A. the object’s inertia becomes 2times greater

B. the object’s inertia becomes 2 times greater

C. the object’s inertia becomes 4 times greater

D. the object’s inertia becomes 8 times greater

E. the object’s inertia is unchanged

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2#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

02.14: An intrinsic property of matter is one that does not depend 2ajd8m2 ykii72o8ux gkt s..e on the quantity of matter present. Which of the following pr jsak2.t 8 22 ydii7mu8oe.gkxoperties is NOT an intrinsic property?

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3#

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04.16: A 20 kg boulder rests on the surface of the Earth. Assume the Earth hazr( b35 fzfrj2s mr3ffzrj 25bz( ass $5.98 \times 10^{24} \; kg$ and $g = 10\;m/s^{2}$ . What is the magnitude of the gravitational force that the boulder exerts on the Earth?

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4#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

09.12: A 5.0 kg sphere is in free fall near the surface of the Earth. Wh q2nu2pqwy ,uxk70c4 vat is the magnitude of the gravitational force acting on the earth by the su0n4,ckq7x2 qwv puy 2phere? The Earth mass is $5.98 \times 10^{24} \; kg$ .

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5#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

00.09: Is it possible for an object’s v)p(s4n kfkf tr7jwr,2elocity to increase while its acceleration decreasr,k7(f2 nsj tf 4wp)kres?

A. No, this is impossible because of the way in which acceleration is defined.

B. No, because if acceleration is decreasing the object will be slowing down.

C. No, because velocity and acceleration must always be in the same direction.

D. Yes, an example would be a falling object near the surface of the moon.

E. Yes, an example would be a falling object in the presence of air resistance.

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6#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

00.11: A certain particle undergoes erratic motion. hjv;i4ud .tdv6q3z k7 isko(5n7u ,r yAt every point in its motion, the direction of the particle’s momentum is ALWA5zih s (3un74quv7,vo;kyk.6dijr td YS

A. the same as the direction of its velocity

B. the same as the direction of its acceleration

C. the same as the direction of its net force

D. the same as the direction of its kinetic energy vector

E. none of the above

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7#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

17.14: A block is suspended in the air a li/5sn5bn tzxb5fzw+ wua.d* +w0fo/ t the end of a string held by a person. The person pulls on the string uniformly accelerating the block upward for a short time. During this time, which one of the following choices correctly identifies the N+ / faxbs/+l0fwwnuo tdzbn*i55z. 5w ewton’s Third Law pair force to the force of the string on the block?

A. the gravitational force from the Earth on the block

B. the force from the string on the person

C. the force from the person on the string

D. the force from the block on the string

E. the force from the person on the block

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8#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

07.18: In which one ofvsmy69r)( gvu k,gr g* the following situations is the net force constantly zero on th*9y, )v gvsg ug6rm(kre object?

A. A mass attached to a string and swinging like a pendulum.

B. A stone falling freely in a gravitational field.

C. An astronaut floating in the International Space Station.

D. A snowboarder riding down a steep hill.

E. A skydiver who has reached terminal velocity.

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9#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

13.28: An object is in free fall close to the (bsef0h ai-jd )h+t l6ground. A person intervenes and slows the object uniformly to rest. Which one of the following statements must be true about the magni (dbh-j0fs +atlh)ie6 tude of the acceleration of the object as it is being stopped by the person? The magnitude of the object’s acceleration is a and the magnitude of the acceleration from gravity is g.

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10#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

98.03: An object in equilibsf18qu0 )5i fug ltls9rium has three forces, F1 of 30 N, F2 of 50 N, and F3 of9ql0s5)sutgfu 8l i1 f 70 N, acting on it. The magnitude of the resultant ofF1 and F2 is

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11#

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01.07: A force of 6 Newtons and a force of 10 newtons can be combinek6tv l4mjjy70 to form a resultant with a magnitudej6m yk4tv 0jl7 of which of the following

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12#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

10.06: Which of the following statements is most c7/xo ,cxiz,;pzsh tc3losely associated with Newton’s x;/z7ho3pccis z, t,x Third Law of Motion?

A. “What goes up must come down.”

B. “For every action force, there is an equal but opposite reaction force.”

C. “An object at rest remains at rest.”

D. “The acceleration of an object is directly proportional to the force acting on the object but inversely proportional to the mass of the object.”

E. “The Universe tends toward disorder.”

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13#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

95.06: The reaction force does not cancel the action force becqk/np+ jid, 7kjl3lhi k/6dx. ause:

A. The action force is greater than the reaction force.

B. The action force is less than the reaction force.

C. They act on different bodies.

D. They are in the same direction.

E. The reaction exists only after the action force is removed.

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14#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

14.14: A box rests on the floor of an elevator. The elevator is av. hl)fbybr/2qags::d9t+ d uccelerating upward. Which one of the following choices best represents the Newton’s Third Law pair force to the gravitational force acting on tdhbdr: vta/us2:b+ gl.q9) f yhe box by the Earth?

A. There is no Newton’s Third Law pair force in this scenario.

B. The entire normal force of contact from the floor on the box.

C. Only a portion of the normal force of contact from the floor on the box.

D. The force of the cables pulling upward on the elevator.

E. The gravitational force acting on the Earth by the box.

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15#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

15.15: A skydiver falls downward through the air with con, p)ldaa3bl3m xedt3 2stant speed. Which one of the following choices correctly describes the Newton’s Third Law pair force to the air resistance a aabpl3d em,) x3t32ldcting on the skydiver during the fall?

A. There is no Third Law pair force for this kind of situation.

B. The gravitational force acting on the skydiver by the Earth

C. The force that molecules in the air exert on neighboring molecules in the air.

D. The force exerted on molecules in the air by the ground.

E. The force exerted on molecules in the air by the skydiver.

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16#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

06.08: A baseball is thrown bzajrf4dzi v2y0 hp,(*y a pitcher with a speed of 35 m/s. The batterswings and hits the ball. The magnitude0* y(f 24 pzzhvjr,dia of the force that the ball exerts on the bat is always

A. zero as it is only the bat that exerts a force on the ball.

B. equal to the gravitational force acting on the ball.

C. larger than the force the bat exerts on the ball.

D. smaller than the force the bat exerts on the ball.

E. equal to the force that the bat exerts on the ball.

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17#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

11.13: A physics book sits at rest on zn funi,3fke 1 6+/ae8-ncl qqa table. On top of the book is a calculator, also at rest. Which one of the following choices is the Newton’s T/ i8zqu+6nn,n3 1a qf eecf-klhird Law pair force to the force that the table exerts on the book?

A. The contact force on the table by the book.

B. The gravitational force on the book by the Earth.

C. The gravitational force on the combination of the book and calculator by the Earth.

D. The contact force on the book by the calculator.

E. The contact force on the table by the ground supporting it.

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18#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

05.06: The students in a Physics I class were in lab conducting an experimens2g-gq a8g w1 x;1 ta(ey;iazxt related to Newton's Second Law. The collected dataa xxz-e1iw1gas gg tay 8q(;2; were displayed on the graph at the right. From this graph, what conclusions can the students make?

A. The mass of the system was constant.

B. The acceleration of the system was constant.

C. The force acting on the system was constant.

D. The force acting on the system is not related to the acceleration of the system.

E. The force acting on any system will always be less than 20 N.

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19#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

99.03: If the net force on an object were doubled while at the same time the maj2iwe :rmk l*a-/)an rss of thr-l ar m:a k)ijw2e*n/e object was halved,then the acceleration of the object is

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20#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

96.15: A car whose mass is 1500 kg is accelerated uniformly from rest to a spea +mepkm4er0uv: 4 2+edd h7iled of 20 m/s in 10s.mi evme+pa40u h :+d42el 7kdr The magnitude of the net force accelerating the car is:

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21#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

99.05: A tractor-traic4o(3mv;i2hlw/cd1t oax c(wler truck is traveling down the road. The mass of the trailer is 4 times the mass of ti ;d(a2 (vcoo 1clt4chwmw/x3 he tractor. If the tractor accelerates forward, the force that the trailer applies on the tractor is

A. 4 times greater than the force of the tractor on the trailer.

B. 2 times greater than the force of the tractor on the trailer.

C. equal to the force of the tractor on the trailer.

D. 1/4 the force of the tractor on the trailer.

E. zero since the tractor is pulling the trailer forward.

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22#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

99.16: Which of the following principles best explains why large tractor-tra/9t z ksv62nfa lx:ef9 z6:vdjiler trucks generally accelerate much more slowly that automobilkts:6 9ajlzfe2nx fvzd9:6/ves?

A. To every action there is an equal reaction.

B. Everybody attracts every other body in the universe.

C. A force is necessary to change the speed or direction of a body.

D. The total momentum of interacting bodies is always conserved.

E. The acceleration of a body is inversely proportional to its mass and directly proportional to the external force acting on the body.

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23#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

99.19: A 50 kilogram skater at rest on a frictionless rink thrfjv4;hf,ze- , nnjlz8d;+bevows a 2 kilogram ballel, d4fe nj+f-v,8vz ;jn z;hb, giving the ball a velocity of 10.0 m/s. Which statement describes the subsequent motion?

A. 0.4 m/s in the same direction as the ball.

B. 0.4 m/s in the opposite direction to the ball.

C. 2 m/s in the same direction as the ball.

D. 4 m/s in the same direction as the ball.

E. 4 m/s in the opposite direction to the ball.

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24#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

00.13: An object near the surface of the earth withqqxjh (g2fo68 a weight of 100 newtons is accelerat h2(6fxq8gj oqed at $4\;m/s^{2}$ . What is the net force on the object?

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25#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

98.25: A car whose mass is 1200 kguoh .)bqbxuu*d n8tvgu: s69, is accelerated from rest by a constant force of 24 suvb8,*tugo 9u n qx.:ubh)d600 N. What is the speed of the car 8.0 s after beginning?

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26#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

98.32: A 3.0-kg block with initial speed 4.0 m/s slides across a rough h8 0tekbh27hc3vm opz0orizontal floor before coming to rest. The frictional force acting on the block is 3.0 N. Howhevh tom2 kz80c0pb3 7 far does the block slide before coming to rest?

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27#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

95.38: A block with i/8nj-nn9obu mnitial velocity 4.0 m/s slides 8.0 m across a rough horizontal floor before coming to rest. The coeffnubmnn-8o9j/ icient of friction is:

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28#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

09.21: A 20.0 kg box remains at rest on a horizontal surface whmqcmgcf6w(s32kj +av9pb68 s+ nx hl*ile a person pushes directly to the right on the box wsh+kfxccl g n *s2mqpam(v96 + 68jb3with a force of 60N. The coefficient of kinetic friction between the box and the surface is $\mu_k$ = 0.20. The coefficient of static friction between the box and the surface is $\mu_s$ = 0.60. What is the magnitude of the force of friction acting on the box during the push?

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29#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

13.16: A block initially moving at 8 m/s accelerates u6lwq7 3gyzqhf f /z3t(niformly to rest on a horizontal surface. The block travels a distance of 12.0 m during the slide. Which one of the fo(fthg/6zf 7q3wy3q lzllowing choices best represents the coefficient of kinetic friction between the surface and the block?

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30#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

00.21: A car of mass m slides across a patch of ice z p 6wp motteh05-7u9nat a speed v with its brakes locked. It then hits dry pavement and sk w-tpz9uo 7 05phe6tnmids to a stop in a distanced. The coefficient of kinetic friction between the tires and the dry road is μ .
If the car had a mass of 2m, it would have skidded a distance of

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31#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

00.22: A car of mass m slides 17u 0cd y,yi -if7t uzpfno59nacross a patch of ice at a speed v with its brakes locked. It then hits dry pavement and skids to a stop in a distanced. The coefficient of kineti09-zyo iy 5u f1du7pnt,nf i7cc friction between the tires and the dry road is μ .

If the car had a speed of 2v, it would have skidded a distance of

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32#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

04.32: he driver of a car makes an emergency stop by slam k)sm-;0rlo ejming on the car's brakes and skidding to a stop. How far wou mkj-lo;)0 esrld the car have skidded if it had been traveling twice as fast?

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33#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

99.39: The driver of an automobile must carefully control eaf9f.jpc.5 09ukao 1x )tudam up- fq:hch of the following devices. Which of these devices can cause an accele.9u)af.0:15dqj fp-pfu hka 9x mo tucration in a moving car?
(1) the break pedal ( 2) the gas pedal ( 3) the steering wheel

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34#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

00.25: The net force on a rocnmn5 k+1yw5hyk (xwg- ket with a weight of 15000 newtons is 24000 newtons. About how much time is needed to increase the rocket ’ speed from 12 m/s to 36 m/s near the surface of the Earth 1k+wywg 5hn-(xmn y k5at takeoff?

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35#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

07.21: A box slides to the right across a horigxdud2g6g za4 4f9 ,*uo -vbwmzontal floor. A person called Ted exerts a force T to the right on the box. A person called Mario exerts a force M to the lef 26x4gdgdaz,u mw*9 ofub4gv- t, which is half as large as the force T. Given that there is friction f and the box accelerates to the right, rank the sizes of these three forces exerted on the box.

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36#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

02.27: The diagram below shows three roller coaster tracks77*,j4ykl cza td8s.v+xv sk) jkkj (u of equal length. Assume that on all tracks the roller coaster carts start from rest at the same elevation and cku7.vt( j)v* 8kjjy,+ la7z kkssx 4dmoves frictionlessly over the tracks to the finish.
If all roller coaster carts start at the positions shown, on which track would the roller coaster cart be traveling the fastest at the finish?

A. CartA

B. Cart B

C. Cart C

D. All would reach the finish at the sametime

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37#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

02.28: The diagram below xugh*u: b 9 hgk/ )2phthjx18upw.7zs shows three roller coaster tracks of equal length. Assume that on all tracks the roller coaster carts start from rest at the same elevation and moves f)xtzw. h*9hs:x2p hug j 8kbu 17h/guprictionlessly over the tracks to the finish.
If all roller coaster carts start at the positions shown, on which track would the roller coaster cart reach the finish first?

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38#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

02.29: Assume the rollercoaster cartrollsx:.heib,5j) f8g7)zbgqe az i vx/pd6 frictionlessly along the curved track from point A to point C under the influenc ,zhpazb7vx. qbf) gx: )g/8ij5ei6ede of gravity. What would be the direction of the cart's acceleration at point

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39#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

02.40: A box with a mass of 50 kg is dragged across the floor by a rope which rq. l2. atv/itvrut; 5wk 3+cbmakes an angle of 300 with the horizontal. Which of the following would be closest to the coefficient of kinetic frict ;rtv+ wi/tbk5v..3au rt lq2cion between the box and the floor if a 250 newton force on the rope is required to move the crate at a constant speed of 20 m/s as shown in the diagram?

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40#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

04.40: A 6.0 kg block initially a9y;ze8uosg86 m0t aaot rest is pushed against a wall by a 100 N force as sez; so 98at8auom60 yghown. Thecoefficient of kinetic friction is 0.30 while the coefficient of static friction is 0.50. What is true of the friction acting on the block after a time of 1 second?

A. Static friction acts upward on the block.

B. Kinetic friction acts upward on the block

C. No friction acts on the block

D. Kinetic friction acts downward on the block.

E. Static friction acts downward on the block.

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41#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

05.10: A homeowner pushes a lawn mower across a horizontal pat4 /ppfw)yu )spm(: ,ijqf 6yltch of grass with a constant speed by applying a force P. The arrows in the diagram correctly indicate the directions but not necessarily the magnitudes of the various forces on the lm)uwpys6:if f4(p )/qljyt p,awn mower. Which of the following relations among the various force magnitudes, W, f, N, P is CORRECT?

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42#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

06.14: A book leans against a crate on a table. Neither is moving. W6tts az8,sxz0hdc(22qn , vookz ;iz jx5k8y8hich of the followixhzz;yo jic 2ttos8,0a8x5,( 28zqnvskk zd6ng statements concerning this situation is CORRECT?

A. The force of the book on the crate is less than that of crate on the book.

B. Although there is no friction acting on the crate, there must be friction acting on the book or else it will fall.

C. The net force acting on the book is zero.

D. The direction of the frictional force acting on the book is in the same direction as the frictional force acting on the crate.

E. The Newton’s Third Law reaction force to the weight of the book is the normal force from the table.

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43#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

06.15: A crate of toys remains at rest on a sleigh as theva:oar+ ar55b1ve*f m sleigh is pulled up a hill with an increasing speed. The crate is not fastened down to the sleigh. What force is:oe+a1 brvfa *5amr5 v responsible for the crate’s increase in speedup the hill?

A. the contact force (normal force) of the ground on the sleigh

B. the force of static friction of the sleigh on the crate

C. the contact force (normal force) of the sleigh on the crate

D. the gravitational force acting on the sleigh

E. no force is needed

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