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 of an objecvq cw86p;;3m 0 b)x)w0yw*,rlxui bffe w lk/wt 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 not def zzlvozv) 1q5vhj88 :pend on the quantity of matter present. Which of the folloh fq8v8zv1v:)o5 z jzlwing 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 Earbg / *qrhzl4a13tru a0th. Assume the Earth has mass q1bat 40/rrua 3h*lgz$5.98 \times 10^{24} \; kg$ 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. What is a/fid gxgjgg cm21i20r.fk* 8 the magnitude of the gravitational force acting on thg2*g1. cagmd jkgi frx8 /f2i0e 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 increase while its acceleraj1m(9 lxy8f y4 (tvk; igmxm3qtion decy mxfjvy1( q(3m4i89g;kt mlxreases?

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 unde 5;p.(r)e d zlptn1efdrgoes erratic motion. At every point in its motion, the diref 1n.5pezt(pel d)r d;ction 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 in the air at the end of a string held by a peeqw9j0 .n;nh z0suwe1vg *;cv rson. The person pulls on the string uniformly accelerating the block upward for a shorte;0h. g91e j c0wnz*n;vvqu ws 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 follo 5 s4,u3t( xwib*h(fp v4mqeawwing situations is the net force constantly zero onwf btm5x p(u,i svw4 3ahq*e4( 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 fall close to the ground. A person intervenes and slf)vn;j,zlj; wo2/ msjows the object uniformly to rest. Which one of the following statements must be true about the ms)j2wm; /,j; j zlvnofagnitude 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 tj*a co z-:fsm;hree forces, F1 of 30 N, F2 of 50 N, and F3 of 70 N, acting on it. The magnitude of the re*c-z ;ojf:m assultant 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 combine ea(9d*a( va,mkjvdpy 4:aa6m to form a resultant with a magnitude of which o(ayvmp kd9: 4aa(avm* 6ed,jaf 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 statementbta3*dtc nn-d4 9ug l3ncx3.is is most closely associated with Newton’s t3l 9n.n 3dig b3 4ndax*cu-tcThird 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 czcc7bl nz*5xd4:p+bob , z ds:ancel the action 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 floork0moq71)ii bv a*+k vr of an elevator. The elevator is accelerating upward. Which one of the following choices best represents the Newton’s Third Law pair force to the gravvi 1mk b+v70r* aioqk)itational 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 downwar: ,2m6 dgx jv a0/l,mon4k9.mdsatkozd through the air with constant speed. Which one of the following choices correctly describes the Newton’s Third Law pair force to the air resistance acting on the o j/a9mm4kzgm,dvo,t0l.dxans :62k 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 of 35 m/s. +dsrg)s6t4m )fd v c.m The batterswings and hits the ballt m+g4 f.s)mrc sddv6). 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 of the book is a calculate a*3qhsyugiz0 u4 75kr+ /bswor, also at rest. Which one of the following choices is the Newton’s Third Law pair hq/ *yez47 3gsu5brawuki+0s 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 s05c 0eiq 4a -qf-;e1o ohzqsjlab conducting an experiment related to Newton's Second Law. The collected data were displayed on the graph at the right. From this graph, what concf0q4ah -co0eeoj1s5 zs; qi q-lusions 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 werwegb*ft qn(h p9.v1i;k3fso+5d ss :he doubled while at the same time the mass of the object was halved,then the acceleration of the objd n 3.bo ;p*i5:qesf9wkvght+h s(1fsect 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 accelehqvhozf uu5+49 / mj/yrated uniformly from rest to a speed of 20 m/s in 10s. The magnitude of thejh5/9zoqv4f+/hm yuu 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 the rol.y2qy 4-x/rb ee-bil ad. The mass of the trailer is 4 times the mass ofyebyr. x4-/b2 il-lqe the 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 pri7pk(+t 5ut,yagk6 wgq nciples best explains why large tractor-trailer trucks generally accelerate much more slowly thkq 6k pg wy(u,t+g5t7aat 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 ska d)e7bkl,u)f f2x,tklter at rest on a frictionless rink throws a 2 kilogram ball, )ue d)kf7kll x,2 fbt,giving the 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 ead jz14pbr.4s prth with a weight of 100 newtons is acceprbzp 14. dj4slerated 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 by a consm)u:ilp lsjw.gmq cr,35j u7 .tant force of 2400 N. What is the speed of the car 8.0 s after beg)3gui ,r:msjq .wp.jlmcu5 l7inning?

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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/d(yaj v*puno,k*x /2zs 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 before coy*jazdkvn *2o (,pxu/ming 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 8.0ljn.3:tv 4wrm+fvu +f m across a rough horizontal floovr4fn3+t f +l .jv:wumr 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 at res;/wgu )kp*,psex j8 rbt on a horizontal surface while a person pushes directly to the right on the box with a force of 60N. The coefficient of kinetic friction between the bo ,g/w8ebrk)s;up*pj xx 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 initialxth9rv +pe) 2aly moving at 8 m/s accelerates uniformly to rest on a horizontal surface. The block travels a distancev9 t2xe)hpa +r 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 zr fz(*a0ln-c 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 f0(zcz*-rn la 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 t+/k 1h8ette km slides 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 distance+8tek1k /htted. 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 emerge z o: cq77k,/prdl;cxwncy stop by slamming on the car's brakes and skidding to a stop. How far would the car have skidded if itdxw/ p:7 locq;7zrck , 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 t;bi*jnh w xz-ml6tr5q +-hj:bhe following devices. Which of these devices can cause an acceleration in a movin6l-*hh:;5 itnrx-bq+ zbwjmj g 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 r59+ho6-l nv )phz jgxq/ rtc:newtons. About how much time is needed to increase tq6hp- z/9t):+hn c5vlrg jr oxhe 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 floor. A person ca:qmv u -im,my5zu.w9dlled 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 sizes of these three forces exerted on th - mu,myz:.uq5wvdim 9e 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 sdf,oedm*+vk-.o ,tw tracks of equal length. Assume that on all tracks the roller coaster carts start from rest at the same elevation and moves frictionlessly ovedo-.wfetkvd +,mo, s*r 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 equal length. 8a)xb p y(cwv1Assume that on all tracks the ro8abwc y1)x (pvller 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 frictionlessly along the curved track bccebu9t ej6gv.gf1;i)dp.:/e,n izfrom point A to point C under the influence of gravity. What would be the directfu :bie )j .6,i9;1/ezpegt dncvgbc.ion 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 khf*h9j: ov)v kg is dragged 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 cvv: hoh*kj)9 frate 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 apt va5/w; *dbigainst a wall by a 100 N force p atd 5v*b/wi;as shown. Thecoefficient of kinetic friction is 0.30 while 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 across a horizons2xon+ skr6 j)tal 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 reljk2) rso6nxs+ations 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. 6vi;uwfulyi:yn; y.3Neither is moving. Which of the following statements concer;3f;: lwn.uu 6yiyyiv ning 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 a slea9ux l gp x fwqb7b*0sxaa:4eh66.h-righ 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 fxr:6 ual *a 6qg9b w7h .pa0sfhe-xbx4or 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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