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 ofa+ ktgf.9*c :+h;untx+tgpev 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 t3(rf+7 b5x4 nbmfiqnvoe38(h qwm;enhat does not depend on the quantity of matter present. Which of the following properties is NOT an intrinsic property? m8bi7f qnen +n43;vh(mo3ew q (fr5bx

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3#

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04.16: A 20 kg boulder rests on the su:e qc(kd kjy)l3g: e,krface of the Earth. Assume the Earth has mass d3e lq:)y(: ,gkkkcje$5.98 \times 10^{24} \; kg$ 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#

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09.12: A 5.0 kg sphere is in free fall near the surface of the Eewn*8 8 hrf0xxu* xkh;arth. What is the magnitude of the gravitatio*rx *xnh8uwef x kh8;0nal force acting on the earth by the sphere? 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 ob:h cr w75a1gbhlz3ul/(sv a.pject’s velocity to increase while its acceleration dc. z/pv7hb:5l h3g srw(1ualaecreases?

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. At every point in its mot xatqwdj:(( z39 qjch3ion, the directj atw q9z3 3jcqhd:((xion of the particle’s momentum is ALWAYS

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 inr: jvyc,a*ncqu:3z8b the air at 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 tny*,ccr3av q z:jub:8he following choices correctly identifies the Newton’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#

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07.18: In which one of the followinvl3w-x3ss ;phie 23ong situations is the net force constantly zero on then-e2o3sl i3ph ;3svwx 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 frs n *a/bwxi)*lee fall close to the ground. A person intervenes and slows the object uniformly to rest. Which one of the following statements must be true about the magnitude of the acceleratiow * *nb/)isxaln 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 equilibrium has three forces, F1 of 30 N, F2 of 50 N, y-yoct;8-fs xand F3 of 70 N, acting on it. The magnitu8cy-t; ys -xofde of the resultant ofF1 and F2 is

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11#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

01.07: A force of 6 Ne*bzl1i 6rldg.mrm m v37ve 0cwc;e4*s wtons and a force of 10 newtons can be combine to form a resultant with a magnit v eebi1m4c**sr; lg 37lzwm.0r v6dcmude 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 closely associated wih;, ig,f,qymj th Newton’s Third Lq ;,ym,higj,f aw 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 p7w8+*asyhgbv n)c p d6eqa9.force because:

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 el emofzmu4-( l8*wlx iijq (w7uo(u8z,evator. The elevator is accelerating upward. Which one of the following choices best rei8(ief*wqzzmwo4x-lmu,7l j u(8 (oupresents the Newton’s Third Law pair force to the gravitational force acting on the 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 constant spee1bl ppp*x(r0 pd. Which one of the following choices correctly describes the Newton’s Third Law pair for1rxp0(ppb p l*ce to the air resistance acting 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 sg60,z.v33n ogw z yfnomb4y8 by a pitcher with a speed of 35 m/s. The batterswings and hits the ball. The magnitude of the force that the ball exerts onmyv8 ,n go3.o3yz wf6gn4zb 0s 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 a table. On topk68z wud hanl9,pu)1kb: 6dxy of the book is a calculator, also at rest. Which one of the followikun1 a:yhd6,6 u98dwbkzlpx)ng choices is the Newton’s Third 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 i;f ru;uqk8 c ed i,j0dkk 3(tnk*;i+rlq/oh2hn a Physics I class were in lab conducting an experiment related to Newton's Second Law. The collected data were displayed ddk/ 3fk 8ro;;+uhncq0it hu* j qer2lik ,(;kon 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 fo (ki87 pd1kjwsrm3.ou rce on an object were doubled while at the same time the mass of the object was halved,t7km ids 8(w31 kprjo.uhen 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 kgin. 9a9 pfc-z0r w4ffg is accelerated uniformly from rest to a speed of 20 m/s in 10s. Th4zwcf apf-f 9.gni09r e 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-trailer truck is traveling down4y6r xn(u,ao:lh9tg0op nb.v the road. The mass of the trailer is 4 times the mass of the tractor. If the tractor accelerao.vlra (obtp9g, h n4yx06n: utes 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, r7*lrrwnp,r best explains why large tractor-trailer trucks generally accelerate much more slowly that automobir l ,*wrr,rp7nles?

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 throws a 2 kilogi7+ 5plrx/pl8f +onur ram ball, giving the ball a l+8ox/u i rf nlpr+p57velocity 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 with dp nprrv2 zbcrj1h-d ;/ixs),ym/ z5 0a weight of 100 newtons is accebmi;rpz,5n zr //-xph c v2dd)0ys j1rlerated 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 io9ivw k 2p8 ;::cl05n ucgo ure-5spkwj4+yxes 1200 kg is accelerated from rest by a constant force of 2400 N. What is the speed of the carsir- vwx;c4kge p29jlwo5 u0n:+uo py e8k:c5 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 io2hq0j t5+xsa2ur s*l2 5oxv speed 4.0 m/s slides across a rough horizontal floor before coming to rest. The frictional force acting on the block is 3.0 N. How far does the block slide beforeu2h+5 2 oir2s x jvqltxa0so5* 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 initial velocity 4.0 m/s slides 8.0 m a3p5hoio;z h.across a rough horizono pa;5oh.z h3ital floor before coming to rest. The coefficient 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 su +un6w;a3joat rest on a horizontal surface while a person pushes directly to the right on the box with a force of 60N. The coefficient oja3+ u6wn ou;sf 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 moc 6zvs2*i- djjving at 8 m/s accelerates uniformly to rest on a horizontal surface. The block travels a-s *vjzc6ji2d distance of 12.0 m during the slide. Which one of the following 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 pat4)5rcxklm no3ch of ice at a speed v with its brakes locked. It then hits dry pavement and sk kxnrc5)o3l 4mids 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 across a patch of ice at a speed v with its 3sxm,iljnci:(,8wsxc l 22e b+ ;dcghbrakes lock l:c cgndj +eh( ;sixis,32lwmcxb82,ed. It then hits dry pavement and skids 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 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 slamming on kvog 7-j2lq74ni0 25tbshqck the car's brakes and skidding tnbi524-qgqkh7 lvk 0s2c7tjoo a stop. How far would 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 contrpy0*mg a8i+ f(hveg ,h1p1wq+jgvcs5ol each of the following devices. Which of these devices can cause an5q,1 8ggf0e +( j +1ahvmpgysvip*wc h acceleration 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 rocket with a weight of 15000 newtons is 24000 )shs/to +ff5knewtons. About how much time is needed to increase the rocket ’ speed from 15fh+f/ts sk o)2 m/s to 36 m/s near the surface of the Earth at 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 33o;(n sre+kplvj-ju q7w uh9to the right across a horizontal floor. A person called Ted exesqrl3 ouhjjk7v(e;3+9npw u-rts a force T to the right on the box. A person called Mario exerts a force M to the left, 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 threz rjjy080d 8:rt*iob ge roller coaster tracks of equal length. Assume that on all tracks the rol 8rg08o*jr t0b:iz jydler coaster carts start from rest at the same elevation and moves 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 shows three roller coaster trackq6wxx;oq;wmi(5y,r us of equal length. Assume that on all tracks the roller coaster carts start from rest at the same elevation and movqxxu 6wymr;5, (;oiw qes 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 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 cai- e)kkl-x cs7rtrolls frictionlessly along the curved track from point A to point C undekkie 7c sx)-l-r the influence 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 dragj- o0),zh(ae ua: n (l+ntkwdwged across the floor by a rope which makes an angle of 300 with the horizontal. Which of the following would be closest to the coefficient of kinetic friction 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/s0,ntkowe) aa(-(zn:luh+w j d 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 at rest is pushed against a wall byk97:2z.w nxia,qd tea a 100 N force as shown. Thecoefficient of kinetic friction is 0.30 while the coefficient of static friction is 0.50. What is true of the frictd 2 wkzxa.ni79q:at e,ion 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 pu;r1x6kxom mzeo73 qk8shes a lawn mower across a horizontal patch of grass with a constant speed by applying a force P. The arrows in the diagra 6oomr1 7qkzexm ;k38xm correctly indicate the directions but not necessarily the magnitudes of the various forces on the lawn 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. Which of thevvq(4s wzgu)5u(;b mz following statements cv(( g;w qzubv4u )msz5oncerning 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 od ,uv3e)f3+uhtot8y*y* in ian a sleigh as the sleigh is pulled up a hill with an increasint*v)*+8y 3ai3ytde,ni hfu oug speed. The crate is not fastened down to the sleigh. What force is 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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