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

标记此题

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 a*ei7 fv(ps v :eojb-x7n 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

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

2#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

02.14: An intrinsic property 7hcdwbs9qez cuv15g 1oh9 s37of matter is one that does not depend on the quantity oo77 5h1hc1z9 s9bevqw3sdu cgf matter present. Which of the following properties is NOT an intrinsic property?

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

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 Earth has c; lg) d pbestwg-hs7-;yfjve( whr79k1yo06massk()g ;-7;1fgj w ry6wldtc9 pesvye bho-7s0h $5.98 \times 10^{24} \; kg$ and $g = 10\;m/s^{2}$ . What is the magnitude of the gravitational force that the boulder exerts on the Earth?

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

4#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

09.12: A 5.0 kg sphere 83huui 7crc3sgcqt6,is in free fall near the surface of the Earth. What is the magnitude of the gravitational force acting on u c63ist8 7 rc3c,qhguthe earth by the sphere? The Earth mass is $5.98 \times 10^{24} \; kg$ .

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

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 increa :0wp5rk a t9j/6dcdnvse while its acceleration decreas:5/ rckdjtna9w60dp ves?

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.

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

本习题练习题目来源于无忧得胜-网上国际课程 (https://5edu.win)，学生可刷题练习，扫右侧二维码或加微信xxxxxxxxxx，获取更多资料
教师可以抽题组卷或一键复制本试卷，布置为在线考试或在线作业，全自动判分成绩一键排序导出，省时省力

标记此题

6#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

00.11: A certain particle undergoes erratic motion. At every point in its moti lrr4:y( 3lx /zjmdt vp,7j3iwon, the directp/ rjvxli 7 djmt33w(y:lr,z4ion 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

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

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 blz-zucvqd6+ ubqt+*9 4-f rh fy 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 identifies the Newton’s Third Law pair f6q9 luv*bq d-z4hur+ +zcftf-orce 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

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

8#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

07.18: In which one of the follt8,cq6iwkz h a: ajo),owing situations is the net force constantly zero on kjo,8cq6a , aztiwh:)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.

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

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 groundu3,) f-bgssd gp/7gn w. A person intervenes and slowsg-gsp)b3u /wf dn,7sg 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 acceleration from gravity is g.

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

本习题练习题目来源于无忧得胜-网上国际课程 (https://5edu.win)，学生可刷题练习，扫右侧二维码或加微信xxxxxxxxxx，获取更多资料
教师可以抽题组卷或一键复制本试卷，布置为在线考试或在线作业，全自动判分成绩一键排序导出，省时省力

标记此题

10#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

98.03: An object in equilibrium has n)+ uu(n,2sef;pm)d(crjlnq three forces, F1 of 30 N, F2 of 50 N, and F3 of 70 N, acting on it. The m(e pc(;nf+r2m,nqun)) j du slagnitude of the resultant ofF1 and F2 is

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

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 rz w e(eb 1+8cz7av*qjcombine to form a resultant withvjezr 87qcz1e+* (b wa a magnitude of which of the following

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

本习题练习题目来源于无忧得胜-网上国际课程 (https://5edu.win)，学生可刷题练习，扫右侧二维码或加微信xxxxxxxxxx，获取更多资料
教师可以抽题组卷或一键复制本试卷，布置为在线考试或在线作业，全自动判分成绩一键排序导出，省时省力

标记此题

12#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

10.06: Which of the foll(k,x nrbf):f jxrb7ka 3b.2 ulowing statements is most closely associated with Newton’s Third Lawk(r f 3bf,bxxb): rknj7 .2ual 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.”

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

本习题练习题目来源于无忧得胜-网上国际课程 (https://5edu.win)，学生可刷题练习，扫右侧二维码或加微信xxxxxxxxxx，获取更多资料
教师可以抽题组卷或一键复制本试卷，布置为在线考试或在线作业，全自动判分成绩一键排序导出，省时省力

标记此题

13#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

95.06: The reaction force does not cancelgarhz qpauh2gb )- p8(c4.bh 3 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.

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

14#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

14.14: A box rests oupj1enou ed f6m86tb m0)af**n the floor of an elevator. The elevator is accelerating upward. Which one of the following choices best represents the Newton’s Tf d6t6 *en8o1mmp*) 0bjeuufahird 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.

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

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 9vv76 pmld,dib y:ug+ air with constant speed. Which one of the following choices correctly describes the Newton’s Third Law pair force to the ab digvp+l ,m7uvy:69d ir 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.

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

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. The batte 5krye/p pljoh3e 75-frswings and hits the ball. The magnitude of the fof/hr75joe k ely3p5p-rce 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.

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

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 calcus em 91umz5zp*lator, also at rest. Which one of the following choices is the Newton’s Third Law pair force to the forcez5*9ezm psm u1 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.

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

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 expef2vpw o6*7td lriment related to Newton's Second Law. The collected datal w2d po*v76tf were displayed on the graph at the right. From this 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.

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

本习题练习题目来源于无忧得胜-网上国际课程 (https://5edu.win)，学生可刷题练习，扫右侧二维码或加微信xxxxxxxxxx，获取更多资料
教师可以抽题组卷或一键复制本试卷，布置为在线考试或在线作业，全自动判分成绩一键排序导出，省时省力

标记此题

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 werhk d4q u l3czndd:)8y2e doubled while at the same time the mass of the object was halved,then the acceleration of d8kd h3qdz:)n2cy ul4the object is

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

20#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

96.15: A car whose mass is 15 u(s1: aeyl-,mouxz69 2ahkj d00 kg is accelerated uniformly from rest to a speed of 20 m/s ax9sue6lh 2k:am1(jz-ud oy,in 10s. The magnitude of the net force accelerating the car is:

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

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. The2 d6*kpzet)s;b/by f e mass of the trailer is 4 times the mass of the tractor. If the tractor accelerates forward, the force that the trailer applies ondb*eb2fek6)y /st z;p 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.

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

22#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

99.16: Which of the following principles 1;gr2+t lia (c0j su tstnn b1pbm4+c/best explains why large tractor-trailer trucks generally accelerate much mg1tr(cnit+14; csbp a bms/j0nt u+l2ore 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.

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

本习题练习题目来源于无忧得胜-网上国际课程 (https://5edu.win)，学生可刷题练习，扫右侧二维码或加微信xxxxxxxxxx，获取更多资料
教师可以抽题组卷或一键复制本试卷，布置为在线考试或在线作业，全自动判分成绩一键排序导出，省时省力

标记此题

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 kilogram yf5wyr70k* rkdrblmi n+819q ball, giving the ball a velocity of 10.0 m/s. Which statement describk79i bkynrr5+yq0 1* f8drwml es 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.

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

本习题练习题目来源于无忧得胜-网上国际课程 (https://5edu.win)，学生可刷题练习，扫右侧二维码或加微信xxxxxxxxxx，获取更多资料
教师可以抽题组卷或一键复制本试卷，布置为在线考试或在线作业，全自动判分成绩一键排序导出，省时省力

标记此题

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 4vb n1;h;zrqk newtons is acceleratknvbh;q4r1z ;ed at $4\;m/s^{2}$ . What is the net force on the object?

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

25#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

98.25: A car whose mass is 1)vw c9h *p5 npc;nx lyraxgh+:y14:ih200 kg is accelerated from rest by a constant force of 2400 N. What is the speed of the car 8.0 s after;pgn x+r:ixpn:y1c ah9yh54*)l cvhw beginning?

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

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 initialben (p )y,ea,j speed 4.0 m/s slides across a rough horizontal floor before coming to rest. The frictional force acting on the block ispy jnb(ae e,), 3.0 N. How far does the block slide before coming to rest?

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

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.z,v )c jr*a7m4b s em6t1w*du- m.zbgf0 m across a rough horizontal .,z tremb 4*)uvf6 cjmas m1 bwgdz7*-floor before coming to rest. The coefficient of friction is:

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

本习题练习题目来源于无忧得胜-网上国际课程 (https://5edu.win)，学生可刷题练习，扫右侧二维码或加微信xxxxxxxxxx，获取更多资料
教师可以抽题组卷或一键复制本试卷，布置为在线考试或在线作业，全自动判分成绩一键排序导出，省时省力

标记此题

28#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

09.21: A 20.0 kg box mdwh a byz2eo05,duaj5l)l jofs7+tlru)3 8 ;remains at rest on a horizontal surface while a person pushes directly to )j55a 80o+s, aljdd wb z )teflmo;23y7hluurthe right on the box 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?

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

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 accelerates9 *17iv e8x4e qxdyoyx 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 best represents the coefficient of vyx*qe1xx9 8ie 4dy7 okinetic friction between the surface and the block?

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

30#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

00.21: A car of mass m skt81 jy -bep y2g,n9rjlides 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 coe,1jbnjy e9yrt g82-kp fficient 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

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

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 speedj s a(0*w:.,dap v8(fzicuksa 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 tiresf d:ijwp ca0savk(u8 (sa *z., and the dry road is μ .

If the car had a speed of 2v, it would have skidded a distance of

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

本习题练习题目来源于无忧得胜-网上国际课程 (https://5edu.win)，学生可刷题练习，扫右侧二维码或加微信xxxxxxxxxx，获取更多资料
教师可以抽题组卷或一键复制本试卷，布置为在线考试或在线作业，全自动判分成绩一键排序导出，省时省力

标记此题

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 bdbo*)si 9y-an y slamming on the car's brakes and skidding to a stop. Hobd*soy9 an )i-w far would the car have skidded if it had been traveling twice as fast?

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

33#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

99.39: The driver of an automobile musm7m ,fpqgci:3 t carefully control each of the following devices. Which of thesim c3g,m7 :fqpe devices can cause an acceleration in a moving car?
(1) the break pedal ( 2) the gas pedal ( 3) the steering wheel

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

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 15md/:la2uduq )p0z a3;i4gats000 newtons is 24000 newtons. About how much time is needed to increase the rocket ’ speed from 12 m/s to 36 m/s neaa/ g2;a udl4z td0msiuq :pa3)r the surface of the Earth at takeoff?

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

本习题练习题目来源于无忧得胜-网上国际课程 (https://5edu.win)，学生可刷题练习，扫右侧二维码或加微信xxxxxxxxxx，获取更多资料
教师可以抽题组卷或一键复制本试卷，布置为在线考试或在线作业，全自动判分成绩一键排序导出，省时省力

标记此题

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 act.y,x(l m1 7nkj+lr tvross a horizontal 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 the sizetvl7j ytk.nx1,l+rm(s of these three forces exerted on the box.

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

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 n1 ta g0y3qn+ctracks of equal length. Assume that on all tracks the roller coaster carts start fa10 qgcny 3+tnrom 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

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

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 eaj/2( e7 r3 iaddw/* 4a2chwo hmus+vcoaster tracks of equal length. Assume that on all tracks the roller dc4/mewi j aeahhdo7rw vs/2 +*au23(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?

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

本习题练习题目来源于无忧得胜-网上国际课程 (https://5edu.win)，学生可刷题练习，扫右侧二维码或加微信xxxxxxxxxx，获取更多资料
教师可以抽题组卷或一键复制本试卷，布置为在线考试或在线作业，全自动判分成绩一键排序导出，省时省力

标记此题

38#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

02.29: Assume the rollercoaste bit (k42xihk0rm p l0m.lbi(6r cartrolls frictionlessly along the curved track from point A to point C under the influence of gravity. What would b(6xik pik( 0. h2m4ilmtblr0 be the direction of the cart's acceleration at point

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

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 ,n+y hku 1c917cym;qc pdbqk/which makes an angle of 300 with the horizontcm+1h, qdcpyy 79n;1ub c/kqk al. 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?

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

40#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

04.40: A 6.0 kg block i1nvn6pqf amky6ab0/p+d2r;f(5 c hqpnitially at rest is pushed against a wall by a 100 N force as shown. Thecoefficient rk/p6 61mfn 2ybp;na5+ 0phc(v qfdaqof 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.

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

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 idjbl- z;/7cd +pl2fw 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 magnitudes, Wwp dfl 2b; dc/zi-j7+l, f, N, P is CORRECT?

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

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 82yd1qcdph rhf: p e) 9y65aoemoving. Which of the following statements concerning this situation isodhyyp2ed )he8qr a61p5f:c9 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.

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

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 sleigh as the w2zwykqkscgo5b7 (/p6 k,o q(; vnkk9sleigh 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 in spes6gn29vo 5w(zykw7 ;kk,p(/bko qkqcedup 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

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

账号		自动登录	找回密码
密码			立即注册

网页聊天 (离线可收发)

加微信咨询 (申请一对一课程辅导，加本站学习交流群）

电话咨询：

联系管理员：

查看帮助：

未使用图片

本次作答已使用

1	2	3	4	5	6	7	8	9	10
11	12	13	14	15	16	17	18	19	20
21	22	23	24	25	26	27	28	29	30
31	32	33	34	35	36	37	38	39	40
41	42	43

1	2	3	4	5	6	7	8	9	10
11	12	13	14	15	16	17	18	19	20
21	22	23	24	25	26	27	28	29	30
31	32	33	34	35	36	37	38	39	40
41	42	43

1	2	3	4	5	6	7	8	9	10
11	12	13	14	15	16	17	18	19	20
21	22	23	24	25	26	27	28	29	30
31	32	33	34	35	36	37	38	39	40
41	42	43