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

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1#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

99.36: What happens to the inertia of an object when its vel keoc8/q (4fa39 xdxb,nrz.yyocity 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 one77 0nj+3jeg ewx,gk42m hdnfq that does not depend on the quantity of matter present. Which of the following properties is NOT an intrinsic k g4dfe x0,h+j 2e73gwn7n jqmproperty?

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3#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

04.16: A 20 kg boulder rests on the surface of the Earth. Assumejd18- xp+r9jg ln3r+s,kmuoe the Earth has massrg8p + 9onm d sj-+le,uk3r1jx $5.98 \times 10^{24} \; kg$ 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 fa1 yj )jgb piih4cs:z-hb5r1k2ll near the surface of the Earth. What is the magnitude of the gravitational force acting on the earth by the sphere?hjr4 zspb2jik1 cghb: )5y-i1 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 velocity to increase while its accpd 5xz38yv1 .hf;xh rv7.q jgaelerationxyv5vad; pf3zg8r.. h7h1 qjx decreases?

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*ny cmu(/4 eyc ms8l:h motion. At every point in its motion, the direction of the particle’s moment:/lchmesyn 4 *cy8( umum 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 in the air at the end of a string held by msdpbwqol9t jit 4 x7.1q y42-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 identtqd t.xj b9mol7s4- 1yqpiw24ifies 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#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

07.18: In which one of the following t7/otczi(l ecdkw7 q2fe .ys6-vt+5 a situations is the net force constantly zero on the7 i/- d76yvst2(etktac5le wcofz .q+ 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 ground. A person intertj9-lv)u )c/mlwpx9o venes and slows the object uniformly to rest. Which one of the following statements must be true about the magnitude 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 m9xw) -l)cplm tvoj/u 9agnitude 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 equilibriu w*1brezefl) d /f*)qim has three forces, F1 of 30 N, F2 of 50 N, and F3 of 70 N, acting ld1r*/f) b ei)ew* zfqon it. The magnitude 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 Newtons and a force of 10 newtons can be c29/ssoiv.y3vnd d b .wombine to form a resultant with a magnitude of which of the .yo ssi 3vnv/wd9d. 2bfollowing

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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 b29vj: rkgs pbu23cikkdz :,( is most closely associated with Newton’skj2::s,ckb9u3( bdvr 2 kg pzi 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 bpegdi, g (2x9bal5ls3 ecause:

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 ofw+ptl2nge7( k an elevator. The elevator is accelerating upward. Which one of te72 w+ (glnktphe following choices best represents 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 speed. Wh g*e )u tw-4kyvknlhs++-pc3s ich one of the following choices eksg*-l +4 +vkun 3)cty- hpswcorrectly describes the Newton’s Third Law pair force 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 by a pie-bly9w. :4ds (fzjvm. fy+hptcher with a speed of 35 m/s. The batterswings and hits the ball. The magnitude of the force that th. h-fpsyvl+j:9.wbefm y4zd (e 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 a table. On top of the book is a c- 0 ptlrj.ftf;2na a-nru4 +rpalculator, also at rest. Which one of the following choices is the Newton’s Third Law pair force to the force that theara f-jrpn-tu ;.ntrf 024p+l 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 classetfr:00 c v/1,mb lntwjd.gm( were in lab conducting an experiment related to Newton's Second Law. The collected data were displayed on the graph at the right. From this graph, what concll(j/cv f,t: m1t mben0d wgr0.usions 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 ob+ue4p 7 jkps+(5e9vjxfhdrf5ject were doubled while at the same time the mass of the objec7kp5e5 hpv+frux4(fejd +js9t 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 speed 5yvwedi( y66xr ;yuxih/0ol7 of 20 m/s in 5vd(;i x l0wy yeihuyx/6r6o 710s. 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-trailer trudrbuj2aj ckrny -7nhw(4 lui+q-12:so nw x/( ck is traveling down the road. The mass of the trailer is 4 times the mass of the tractor. If the tractor accelerates forward, the force thaty rw:noujs kjb2ih+-2n7 -/acnlrd1q( x4w(u 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-trailer, hlm **u,rll0sjol 5f trucks generally accelerate*rlu,l0fos , hm5 *jll much more slowly that automobiles?

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 j.nahzd*7 fgq y*g+md 3dl3ghnem) c-:xl ;j: on a frictionless rink throws a 2 kilogram ball, giving the ball a velj:ygg .) d c-dll n xhem+:f7h;gjmz3n*a3*dqocity 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 v/lfg1 9jdhjy+z cm ,6the surface of the earth with a weight of 100 newtons is accelerated,yghzj9j c/v1 +ml6f d 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 isch/7ceds1k s x zm3:-+g l/yfi 1200 kg is accelerated from rest by a constant force of 2400 N. What is the speed of the car 8.0 s after befs e+ikg/mcs-c7 yz:1l3/x dhginning?

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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 speri bzp;.+:s9trj 0ujx ed 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 uzj9.srxj+ti0 p;r b :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 inl0 db9 ql80lrjac0b5 citial velocity 4.0 m/s slides 8.0 m across a rough horizontal floor before comcl lq809dcarb 0bj5l0ing 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 at rest on a hogulw5 sn x:(1lrizontal surface while a person pushes directly to the right on the box with a force of 60N. The coefficient of kinetic friction between the box and the sugn1w sl:x(l 5urface 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 mov//a eev+1 msu;czal pwi0dv:hq4n3 s)ing at 8 m/s accelerates uniformly to rest on a horizontal suv+ 0aph:q4 ee cv salmu;/ds1 wi)/3znrface. The block travels a 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 a2:7mpsdv .czp 4oy:b k 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 :pk 4.yzsm2v 7:cbdpo 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 ofg1+ : pz4kpj/lrk7fj x ice at a speed v with its brakes locked. It then hits dry pavement and skids to a stop in a distanced. The coefficien l/x+zjpk: jk174fg prt 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.p4skc db8w t8 by slamming on the car's brakes and skidding to a stop. How fabpk4tc8wd8 s .r 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 automobi ghcs(y6kh mzd)at;9,le must carefully control each of the following devicesk h9 zm;ghd yta,6s()c. Which of these devices can cause an 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 wi*1lai:jgy 5y,uam r* bth a weight of 15000 newtons is 24000 newtons. About how much time is needed to increase the rocketj5*yga r,yiu1 b a:l*m ’ speed from 12 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 to the right across a ho6adt)8 a7w coarizontal 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 left, which is half as large as the force T. Given that there is friction f and the box accelerates to ttdo aw)c867aa he 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 sh)u nvrx3*k+l 9yp9ngk1+r p ylows three roller coaster tracks of equal length. Assume th9*1pyy) g+k+urll 3npx 9nkvrat on all tracks the roller 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 be1p lz7 sf2syhn7n-)ufrxx,2llow shows three roller coaster tracks of equal length. Assum7u1 ff)l 2srx- ,hsyxlpn7nz2e that on all tracks the roller 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 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 cartrolls frict6ih7345i i :5nsa l vsxomc7jaionlessly along the curved track from point Aa6mis 77a hnvl4jsi i55cox: 3 to point C under 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 dragged across the floor by a rope which ma 9.il65i od sdztii(tf.c,2bgkes an angle of 300 with the horizontal. Which of the following would be closest to the coefficient of kinetic f5i.6ci9zds(lodf it, bi 2g. triction 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 at rest is pushed against a wall bqvqv .2gih+8gy a 100 N force as shown. Thecoefficient of kinetic friction is 0.30 while the coefficient of static friction is 0.50. What2 .hgqv +gvi8q 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 ps))kjqgtm fh;, , uz85g 7bthgushes a lawn mower across a horizontal patch 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 lawn mower. Which of the following relations among the various force magnitud s)ghtb,qu tm ;gjgk8h75f,z )es, 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. Wh c,6y78 jan:b 7sq4wekh-wbvrich of the following statements concerning this sit8 4wa,bj vhy -w6c snq77bek:ruation 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 sleig8 or78by4(sqc 3rwrmx h as the sleigh is pulled up a hill with an increasing speed. The crate is not fastened down to the sleigh. What force is responsible for the crate’s increase in8x bm4wqr3( co 8y7rrs 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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