al physics(kinematics)

用戶40491

2010-06-19 5:45 am

A stone rolls along the curved path under the influence of the gravity.
Which of the following statement is correct?

A)Horizontal speed of the stone is the same throughout the motion.

B)The vertical speed of the stone is the same throughout the motion.

C) Acceleration of the stone is the same throughout the motion.

D)The velocity of the stone is horizontal at each peak.

Please teach me with explanation...Thanks a lot!!!

Ans: D

By the way,would you mind to explain what means horizontal compression force??

Thanks for your help!!!!!!

回答 (1)

choy

2010-06-19 8:38 am

✔ 最佳答案

In this question, only limited information is provided as follows:-
i) the path is curved, i.e. not a straight one; and
ii) gravity is present.

Since the shape of the path and the slope at each point of the path cannot be ascertained, we are not able to judge whether statement A, B and C are correct or not.

It is important to notice that the slope at any peak of the path equals to zero, i.e. the path is horizontal at the peak. As the stone is rolling along the path, it is travelling horizontally at each and every peak of the path. Therefore, statement C is correct.

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