Please solve this problem, thx~=)
A ball of mass m is thrown vertically downwards from height H with speed v. The ball rebounds and reaches the maximum height of H. Is the following statement correct? Why?
-During the collision, the ball loses 1/2mv^2 of energy.
Physics energy&momentum Q
2012-05-30 12:09 am
回答 (1)
2012-05-30 1:03 am
✔ 最佳答案
The answer is apparent. Because the ball is thrown with a downward velocity of v at height H, the total energy E possessed by the ball at this instant is the sm of kinetic energy and potential energy, i.e. E = (1/2)mv^2 + mgHAfter rebound, the ball reached a max height H. At this moment, the speed of the ball is zero. Hence, the ball only possesses potential energy, mgH.
Therefore, the amount of energy lost during collision
= [(1/2)mv^2 + mgH] - mgH
= (1/2)mv^2
收錄日期: 2021-04-28 12:41:29
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