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 ikzr*k fa-u9q:tg 9ol((+rxo q ts 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 depenf7t/)s 5epkqdd on the quantity of matter present. Which of the folloef)tkpq5/ 7sd wing 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. Assume the Earth0bn*+aox l lf5.d,pt,nrt ng- has man d-pn0+xlot ng .lra, fb*,5tss $5.98 \times 10^{24} \; kg$ 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. Wh2 3jqv;napzwqa rezof0 09(+nat is the magnitude of the gravitational force acting on the earth by the sphere? The Earth mass i an+zqj3na00(vq2o ;wz9f pres $5.98 \times 10^{24} \; kg$ .

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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 ld09.hmat,vtb 9 4kmn an object’s velocity to increase while its acceleration dvb,9.aml4mn0 ttk 9hdecreases?

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 particlee7 k-ko ja25 jcsi(r5q undergoes erratic motion. At every point in its motion, the direction of the partik q-kc5a(j5io 2jse7rcle’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 suspende p(dzknx) lv9*h65gv/sh s/rqd in 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 thxs h5 )h9ngp/qrvvl6dz /sk(*e 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* m6xews yisyv8/2.jvqi k .-h situations is the net force constantly zero vi.k j- syvw2/*.xmhe6q8isy on the 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 30suk( wc (x4k;hqznw(u s+q(* tobi zfall 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 magn uw*t 4;q k3(hs+zonkwcxb(q i us(z0(itude 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 ;4kmg lswd ja:p d(y-(three forces, F1 of 30 N, F2 of 50 N, and F3 of 70 N, ym(a;: dg dpjslk-( 4wacting on 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 a64qjxil qx0a -vc4 -bg force of 10 newtons can be combine to form a resultant with a magnitude of which of the followiq4xig4xvqj60 - balc -ng

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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 w+1p+da4;yd rtto mr+f ith Newton’s Third Law afr+ t+mo;d4 dry+p1t 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 fsi;3f2dri1xn / iwub0 orce 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 acceleratihvpo3sq;1q s cq6*ii e.ipum3:r wz**ng upward. Which one of the following choices best represents the Newton’sr3q 6i.eh*w p *;qcums1vzi:os piq3* 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(b-xoq y8y1t)hx nd6gich one of the following choices correctly describes t18 ()ox -bqndghx6y ythe 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 to);ov j i1x2knhrown by a pitcher with a speed of 35 m/s. The batterswingsko1j)2ixo n;v and hits the ball. The magnitude 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 a table. On top fd z,oks1d 8u-of the book is a calculator, also at rest. Which one of the following choices is the Newton’s Ts udk fd,o18z-hird 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 Pov 7wi*7j4o .nvr0b ibhysics 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 this graph, wh 7n0. vrwivi*bo74jb oat 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 doubljeaxe f y4.es7)ysekr p63p2. ed while at the same time the mass of the object was halved,then the acc26s. )erf 7 jsykap. eeyxe43peleration 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 restf n;wz9h3 * d-o1nrynrpx+myx9c.uc/ to a speed of 20 m/s in 10s. The magnitude of the net force accelerwp3d.y;f-u9m r91crc h*o ynz/ xxn+nating 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 t rvh:xat9z(3 ahe road. The mass of the trailer is 4 times the mass of the tractor. If the tractor accelerates forward, the force that the trailer applies on the :a9xv3r (thaztractor 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-trm-. uxziek )ex g-hb+5ailer trucks generally accm-uei-.hxg+zkexb )5 elerate 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 ru5nks l )xcwegmj* .*lnl5. 1nest on a frictionless rink throws a 2 kilogram ball, giving the ball a velocity of 10.0 m/s. Which statement describes n. l*mxl5n5ne)uckj 1*wsg. lthe 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 thefmf/7 2y, ba5gn3 iap-kx-gvk surface of the earth with a weight of 100 newtons is acceler /bk--p3mf7vi2a,kgg y 5fxnaated 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 accelerated from rest 1rml0f pv v51crg6b*aby a constant force of 2400 N. What is the speed of the car 8.0 s al0 6ab5r*c vpf 1grm1vfter 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 horizonbp3 4 fqroq:(ttal floor before coming to rest. The frictional force acting on the block is 3r:qt (p4qfob 3.0 N. How 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 iogd1vwv 4+u2 3b-ee, ykxase 5nitial velocity 4.0 m/s slides 8.0 m across a rough horizontal floor before coming to rest. The coefficient of f-o dwgkaveyv +3245ebus1 ,e xriction 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 whi x (w.4kw7d6yao j;tpmle a person pushes directly to the right on the box with a force of 60N. The coeffic w pdox; 7.ktwjma(46yient 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 unifo1 +movw)n0hq mrmly to rest on a horizontal surface. The block travels a distance of 12.0 m during the slide. Which one of the following choices best represents the coefficient of k1v+)no mq wmh0inetic 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 3a5kyg- *acx eice at a speed v with its brakes locked. It then hits d-kc 35ygaae x*ry 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 slidb fira+dh *u2f*k of39es across a patch of ice at a speed v with its brakes locked. It t+k39uh*fai ffd2 o br*hen 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 stnr 7z3 n(;1qpfgjd c)ikekb80 op by slamming on the car's brakes and skidding to a stop. How far would the cafr e8g1k0p )j7n;qcnib(3kdzr 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 car8 n3h5amp,w0+ b wrmyroq (z +uascw;7efully control each of the following devices. Which of these devices can cause an accelera (u sr,mycz+oa5;pww+7b h a3mn0w8rqtion 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 newxq* 3jyqt-e)j4-kbn 73 h fwuutons 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 jqqju-fk)ty-u3n7x3 b4* hewof 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 horjt:aq(q-s( 51ca qm.xsr mj5axov256 gom yd2izontal 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, wh jxa. jc2y6(dqro:5-q5soamqm 1 v mtx5(2gasich 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 cogoyy46de0 r/ faster tracks of equal length. Assume that on all tracks the roller coaster carts start from rest at the same elevation ag4do yye/ 60frnd 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 tracks of equalbon.cke3n5v fwyut 9)/ yyif;7wk oz/*u;4b j length. Assume that on all tracks the rolle/3ycv 5/n*towunf 9;ji wuy.e;b kyfzk7o b4)r 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 frictia :9gvpq:ryn z+xv l(-wze.gx f *c-6konlessly along the curved track fro:vgw q96.n:k- vyzaz(xlegcx + f*p- rm point A 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 ma4 ;,sypwhav nn .xgzl6.4:uio kes an angle of 300 with the horizontal. Which of the following would be closest to the coeffici6n phsv.a.ou lign:z,x wy; 44ent 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 pushed against a wall by a 100 N fryw8spb*u u9 op :o429cu+tpaorce as shown. Thecoefficient of kinetic friction is 0.30 while the coefficient of static frict p829uprpbo 9su a+:t4yuwc o*ion 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 pushzs1jknk :d .4mes a lawn mower across a horizontal patch of grass with a constant speed by applying a force P. The arrow14 s:.z mdnkkjs 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 movingzna ssn7b2 *-jn51sy y. Which of the following statements conzysj- nssa*b 7n21y5ncerning 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 a8ha (jen w7 okq/v5n,5fun8o a sleigh as the sleigh is pulled up a hill with an increasing speed. The crate is not fastened down to the /5, 8(n 7kaunhawo q 8evjnf5osleigh. 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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