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 in3mx isapida:1hdl*6-1 z w:;c pr5ca kertia of 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 macey4zbxd-jx:pxiug 84 s 4(e *y ve/8rtter is one that does not depend on the quantity of matter present. Which of :eb / pesrvz*ygcx4iu8-(4yej dx4x8the following properties is NOT an intrinsic property?

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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 38u+fat1( j,0b tahwpwi2 lr+lgx3cnEarth. Assume the Earth has mas l2h p+cujnbar3+xwt,18gw il(0 a3f ts $5.98 \times 10^{24} \; kg$ 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 khqb c-)knkh,u n37 nd7a.nb6the surface of the Earth. What is the magnitude of the gravc3kd.khnkubn6 , -q) b7hnna 7itational 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 mj c/17 e81ovatmrvm ayctf9--2x+lw object’s velocity to increase while its acceleration decrmmja+1m-tec la 7v91ov t8-/ rfxcyw2eases?

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 errr;v7 kd- z(lhbjl.zq5 atic motion. At every point in its motion, the direction of the particle’s mome.b(kjr zzlhl57 v ;qd-ntum 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 theher 4 z-8kpn:/2hl( e/kkqrmv air at the end of a string held by a person. The person pulls on the str/4:leerp-hrk zn(k 2hqv8k/ming uniformly accelerating the block upward for a short time. During this time, which one of the 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#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

07.18: In which one of the following situ an) ;j-ijz3ugations is the net force constantly zero on t;jgza- iu3j) nhe 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 intervenes anjfe7n0f, y r.*lbjsh -d slows the obje.fh*bfrle ynj-7s ,j0 ct 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 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 +tdz.j4p :opeforces, F1 of 30 N, F2 of 50 N, and F3 of 70 N, acting o4ejzp.o: td+p n 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 comblmh28a 5h obkf:-: 5javpurh)ine to form a resultantjhhlkr ap2mbf58u)5 a :-ho :v with a magnitude 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+wy6o0bo o )0j5unbdim gkt zz-9-g0k with Newton’s Third Law of Motioo0t9 w y-zi )z-ko50bkbo0gd 6un+mjgn?

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 femzya 00x-o2) 0x(sefmo -qtw p,ut4 iorce 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 elevator. Th su+47onw zby-e elevator is accelerating upward. Which one of the following choices besonbsw7z- y+u 4t 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. xk lxx+b72rl+*s:nynu. uxy w. (df.uWhich one of the following choices correctly describes the Newton’s Third Law p+l.xwxsuy*u( x 7y:xnb.f2l .+ukdrnair 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 pitcher n9bx: bbh.4i vc6cu-pwith a speed of 35 m/s. The batterswings and hits the ball. The magnitude of the fov. 4ccb9 b-h ip:bunx6rce 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 r3hfcoib8,p/by w -pb6 est on a table. On top of the book is a calculator, also at rest. Which one of the followingp/6,b3icbp-who8yb f 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 in a Physic+yairm ( y;i)p6e;m8p .cxdhrs I class were in lab conducting an experiment related to Newton's Second Law. The collected data were displayed on the graph at the right. From thisxi+ea 86m h)yc(i;dymprpr ; . 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 forcvq23pnarh e(8 (s9 trce on an object were doubled while at the same time the mass of the object was halved,then the accelera3nt9(p8hra2( sq vrection 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 fs)4mti uo) dt)ck aolt ,cp):2rom rest to a speed of 20 m/s in 10oliop:), d2tcs )amct) t)k4us. 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 truck is traveling down csaqq.*(l qn5the road. The mass of the trailer is 4 times the mass of theq sqqa5 lnc*(. 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 x *0eyg kcrxwud9 r/d4lpr,pe- 2ob4-large tractor-trailer trucks generally accelde* l9bdcxgy-rr,4/k02pxu-p4 wo ererate 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 on a frictionless rink 8 ukg; -(n;uc-rzsdy vthrows a 2 kilogram ball, giving yur8 d sk--n(;g;vzc uthe 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 with a weight of 100 newtons icncqru7 ic* ws;: +,rys acceleyc;n+ src qwc7,ru:i *rated 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 kg is accelerat.v ighnln.l/* ed from rest by a constant force of 2400 N. What is the speed of the carl/*vl .ingn .h 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 sqjr ,ms-0 bkq*lides across a rough horizontal floor before coming to rest. The frictional force acting on the block is 3.0 N. How far does ,q* msb- 0rkjqthe 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 initial velocity 4.0 m/s slides 8.0 m al zba8e8y v+c s,4e6q1c/jub q :uxm3rcross a rough horizontal floor before comin +lcuyxbbmejes8,rz34 v6q aq/c u:1 8g 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 horizontasfvps2c knvr(eq)y a+; y *z2:l surface while a person pushes directly to the right on the box with a force of 60N. The coefficient of kinetic friction betweencyp kysq*2n; e2r+z v vfs(a:) 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 uniformly to restz, h2ceeh)m:3 t fz8dvyr/2nu on a horizontal surface. The block travels a distance of 12.0 m during the slide. Which one of the following cz,zmht/2cufryn 8h 2e: d)3vehoices 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 st x d2bxdb1sh1+(n)liks1y0wo( yoz8 lides across 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 kinetic friction between the tires and the dry road is μ .x z+0 yohxbk(o)18t dly1s 2ndibws(1
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 kn85,kzemvnh q65(yu v with its brakes locked. It then hits dry pavement and skids to a stop in a distanced. The coefficient of kin (ek55vnun y,h8kzq6 metic 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 su ;xdm e5k6mk+b7jif.lamming on the car's brakes and skidding to a stop. How far would the car hk;5d i 6.u+j fembkmx7ave 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 each of the followinss+( n efj 1/jy)tzsl7g devices. Which of these devices can cause an acceleration iyjf1s l+nsjsze) 7t/( n 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*qt)f x2k1m7jepw0kma i 3kx; 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 neafpe m*jx 3 ki2a7 0wkx;)tmk1qr 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 horizontalh n)-2w0 0ojtw;gfv hxir42gi 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 the right, rank owg 2iwj-0 grvf2h)n;h 0 4txithe 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 roy8e 9;c rtx 7aqqj/as)v-ba: eller coaster tracks of equal length. Assume that on all tracks the roller c)a -e:8av;cqj y7ae qt9 r/sxboaster 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 coak/ jyfqx 9*e b2d/hdd5 ;11it2 mnomooster tracks of equal length. Assume that on all tracks the roller coaster carts start from rest at the same elevation and moves frictionless d* dbmyqek5 nt1;i/ h29of/doj1xo2 mly 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 frictionlessly along the curved tracwho0 73t eu ,;3jajeubc6l1 yz sk.a5dk from point A to point C under the influence of gravity. What would be the direction of the cart's accelejs.u3k5b;z uw h yae37aej10oct, 6ld ration 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 draggedk0m.wgw.epk 5e u,874 iww apg across the floor by a rope which makes an angle of 300 with the horizontal. Which of the followiee0 8w iw4kpw5apk,w 7.ggu.mng 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/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 puthxutr4ss9 o57;ss .wshed against a wall by a 100 N force as shown. Thecoefficient of kinetic friction is 0.30 whiles.r7o 9 thsxu54wsst; 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 acro5sfes ) qy. /wa:* rp1m6 kpetwoc9w,rss a horizontal patch of grass with a constant speed by applying a force P. The arrows in the 1 o .ap qw : fs)emse65wry,wp/9*tkcrdiagram 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 zw*iy8cf tq8/ is moving. Which of the folc/ 8q*8 itfzywlowing 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 toyweyt,mu 4 +cy;).4byom jqtri*86ruts remains at rest on a sleigh as the sleigh is pulled up a hill with an increasing speed. The crate is not fastened down t44o+e;t*t bqyrmutm .w ry8uc j),i 6yo 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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