大学物理A（Ⅰ）(重庆交通大学)mooc慕课答案2026年版满分测试WYC

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起止时间:2020-03-09到2020-05-23
更新状态:已完结

Chapter 3 Kinematics in More Dimensions; Vectors (2) Chapter 2~3 Test

1、 Which of the following formulas is true for all types of motion?

A:
B:
C:
D:
答案:

2、 Which of the following ideas is helpful in understanding projectile motion?

A:Acceleration is +g when the object is rising and -g when falling.
B:The horizontal motion is independent of the vertical motion.
C:The velocity of the object is zero at the top point of parabola.
D:In the absence of friction, the trajectory will depend on the object’s mass as well as its initial velocity and launch angle.
答案: The horizontal motion is independent of the vertical motion.

3、

A:
B:
C:
D:
答案:

4、 If the motional equation of a particle is expressed as , which of the following statement is true?

A:It is a uniform circular motion.
B:The path is a parabola.
C:The radial acceleration is
D:The speed is v=2t.
答案: The speed is v=2t.

5、 If we choose two different reference frames to analyze the motion of an object, the description of motion can be different.

A:正确
B:错误
答案: 正确

6、 In 1-dimentional motion, if we know the accelaration of an object, then its velocity can be expressed as:

A:正确
B:错误
答案: 错误
分析：The accelaration is not necessary to be constant, so we have to use an integral to express velocity.

7、 If a particle has a constant speed, its acceleration equals 0.

A:正确
B:错误
答案: 错误
分析：If a particle has a constant speed, its tangential acceleration equals 0.

8、 In a circular motion, the acceleration is always perpendicular to the velocity.

A:正确
B:错误
答案: 错误
分析：Only valid when it is a uniform circular motion.

9、
答案: 140

10、
答案: [79.6,80.1]

11、 An object moving in r =100m circle satisfies: , how much is the magnitude of acceleration when t=1s?
答案: 15

12、 Someone must get directly across a 160m wide river (from A to B) in the minimum time. The river’s current is 0.8m/s, he can row a boat at 1.5m/s, and he can run 3m/s. Try to find the best path he can take, and what is the minimum time for the crossing? t = __ s
答案: [123,125]

Chapter 4 & 5 Dynamics： Newton’s Laws and Application (2) Chapter 4&5 Test

1、 A conical pendulum composed of a massless rope (length L) and a bob (mass m) is shown in Figure. How much is the period for the pendulum?

A:
B:
C:
D:
答案:

2、 A mass m slides down along a circular track (radius R) from position A with no friction. When it arrives the position as figure, how much is the normal force N acted by the track?

A:
B:
C: