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 2wz -j;7df rts8 zbob3of 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 noto:v+cp+(kah no clr/: depend on the quantity of (khnc+orc :lv +p:o/amatter present. Which of the 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 Earth. Assumesae/: , vw 2yjt2jwsg0 the Earth has masss j:we/y2w js2v,tg0a $5.98 \times 10^{24} \; kg$ 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 th j9u(c jb40xtra7(g).npj.rc d(d rmg e surface of the Earth. What is the magnituded.jc.pa)xr4(dcjb g((7 ju9tg r0 rnm of the gravitational 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 object’s velocity to increaseb(l1 ;sj;cwwtgb0 oq. while its acceleratiocj;b0wqobw1 g.ts( l;n 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 erratindxdo, vx6o d9wh(yk0x+ff 5 9(bipe6c motion. At every point in its motion, the direction of th+o6eoy( dfk5f(wb 0 xv9i6pxh9 x ddn,e 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 in the air at the end of a stringhnl :keo+w 8l*1 tmnq- 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 iden:kt+q wh mon8* ll1-netifies 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 situations is the net force constanmk,rw k26t e/tk.:cz7cwj6pb tly zero on the :6w ck2trz7w /jce6kp.,bktmobject?

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 interven p3ycwow1un s0kqn/ 4f-95n dyes 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 magnitude of the accelerny0u5pncfw39y qs1kd /o nw 4-ation 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 9+3hba :jig m/gdk t qmm7wysz.j),d5of 50 N, and F3 of 70 N, acting on itysk md)m/ih5 t b37agq ,djmw+j9:gz.. 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 forcuk/j4/2d6 5lsa rd tsoe of 10 newtons can be combine to form a resulta6jd u5/d 4/s rslotka2nt 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 as 2mz oi4x;jy4rsociated with Newton’s Third Law of Motior j;4zi42o xmyn?

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 acti n1m5ojrtv(n:d lq9 q: u2v8gfon 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 elevator. The elevator is acceleratingv.jp*: 3dn ,birss y;y upward. Which one of the following choices best represents the Newton’s Third Law pair force to th;yp3dv.,b*js:rins y e 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. Which onl( ib )l6wz-5 tv suencv5+j8ne of the following choices correctly describes the Newton’s Third Law pac) nuj-(nv l5 ls5vi+e8wbzt6ir 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 with a speed of1xtggy/8ur : k 35 m/s. The batterswings and hits the ball. The magnitude of the force that the ball exerts gt k1 u8xr/yg: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 si )txql up0k*,zts at rest on a table. On top of the book is a calculator, also at rest. Which one of the followi)pt *0ql xuz,kng 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 Physics I class were in lab conducting an ezye5n:k fz; k(rj 910w ,boawqkh))gv xperiment related to Newton's Second Law. The collected data were displayed on the graph at the right. From this gra 0e f(bh9y1) rknw vzw5;j,o gkk)q:zaph, 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 )fkfm u r,6e4f4 in5isat the same time the mass of the e ,m5u)sf4i k6ifn4rf 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 u+,4ahhj5 ,xtig))i 2xloqfpfw . q g-zniformly from rest to a speed of 20 m/s in 10s. The magnitude of the net force accelerating il+hz t5j-q) w2) ,pff.h x,ggxi4oaqthe 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 the road. The mass of the trbxrs cs(sbf;0 hg2ua ,ut12) kailer is 4 times the mass of the tractor. If the tractor accelerates forward, the force xu2b1 2),(sbcktr;fh a0 sgs uthat 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 tractorzs;18,y8nyik v2 ntwg-trailer trucks generally iktn ,8gz2y; s1wny8v accelerate 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 throws a 2 kilogue9,9cn*oef0 gh *dwkq v1gv5ram ball, giving the ball a velocity of 10.0 m/s. Whicfk5u9q 1*,vvgdeoc * 0w9neghh 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 9 ;kcrz1w lz1g9iz6 u9w v,aw/agriu6of the earth with a weight of 100 newtons is accelerated awlc6 ;k1rzgvu 9a9 9zrw g w/ui,a1iz6t $4\;m/s^{2}$ . 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 1xg6k)eyf 6n/uz pc87k9am)yc4 0qyez200 kg is accelerated from rest by a constant force of 2400 N. What q4zf )xk)78p6/0c yegyym9e 6akczunis 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 horizontat 8 ruw--qrw bw-;3c pzbq8k:qwwl57 ;rnego,l floor before coming to rest. The frictional force acting on the block is 3.0 N. How far does the block slide before coming tbw5k rernwpcw-, w;87;bwrq3u -:qgzt - qlo8o 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 sbk z bos+m m+sf5nq/(* o.e;nrlides 8.0 m across a rough horizontal floor before coming to rest. The mf bn+zsre5s ./+ (;om*kboqncoefficient 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 while a person push9lvmxv, :ltnp 6) ooh4q ak* 0.41iod3 iucdudes directly to the right on the bo0l4quv dvto43)ihn d1o c*k au,l6 o9d:.xipmx with 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 mwiz-dq h85jrr m n:b r05p/2fih -too2yf84mhoving at 8 m/s accelerates uniformly to rest on a horizontal surface. The block travels a distance of 12.0 m during the slide. Which one of the following choices bem-2ffmr /j84hinw p-yq5 rt hi od:b2h5or z80st 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 s bo2. 1 s+xd-bajgr0io+qw) bdlides across a patch of ice at a speed v with its brakes locker+1g 2dbwosx0oj bq )db.a-+id. 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 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 spee+jdnli3 6n,m d*lxb8 sd v with its brakes locked. It then hits dry pavement and skids to a stop in a distanced. The coefficient , md6n3nlbd j*l+sx8i 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 the car's brab q31ysy)iwg;k urn 8lnat: 37kes and skidding to a stop. How far would the car have skidded if it had been travel3stkniuq81 a )wlrg n;3b:7yy ing 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 followin)3 uawr+g9cm jg devices. Which of these devices can cauaj wr)3g9+ucm se 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 rocke1cll2/ s*dyb vt with a weight of 15000 newtons is 24000 newtons. About how much time is* cl/db1y2s vl needed to increase the rocket ’ 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 horizontal flmg2glwib (f cq .dcrjd1*+ 0l1 e:ozk.oor. 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 the mqg.r i1+.0(e1d:ccdljob2 f*gw z klsizes 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 tracks of equal length. Assug+fv 6le /k33ps:ve7mckr*cbme that on all tracks the roller coaster carts start from rest at the same elev/ sk3g6 3e+rbv vpcm*l:e7 fckation 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 rol8i+17rjv/vuu e xcqd: ler coaster tracks of equal length. Assume that on all tracks the roller coaster carts start from rest at the same elevation and moves frictionlessly over the trackivd8 qru/:cx uv1e7+j s 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 curvef 0he0 cgtp(;rd track from point A to point C under the influence ;0frpetg hc0(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 m(s oyr h3.xv2xpwt86c+,njbfloor by a rope which makes an wmbx,h2 6pvcjo tr+ys.8( x3nangle 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/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 f9r 4xlb ykex.be+7.fis pushed against a wall by a 100 N force as shown. Thecoefficient of kinetic friction is 0.30 while the coefficient of static friction is .+4x xebfe 7.ryfk9l b0.50. 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 patch ofcj*9w 70jgs9f0 utbnl+2cpk x grass with a constant speed by applying a force P. T97bfp x+nujk 0j2tcl*cs 09g whe 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 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 ofszd4:n -r owt8 the following statements concerning this situation is CORRECT?4 norztw-:8s d

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 e s zhj *r6ldo62q(w9jremains at rest on a sleigh as the sleigh is pulled up a hill with an increasing speed. The crate is not fastened down z(oq6 jedj9rslwh2*6 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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