A classical mechanics problem by anurag jha
Classical Mechanics
Level
2
A body has kinetic energy E at the angle of projection for max range. Its kinetic energy at the highest point of its path is?
zero
E
E/2
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1 solution
Maximum range (if all friction is neglected) occurs at 45 degrees of elevation, therefore vertical and horizontal initial velocities are equal. At the highest point, vertical velocity is 0 but horizontal remains constant. Therefore, if v was the initial velocity, and u was the initial horizontal velocity, then: v 2 = 2 h 2
Since E = . 5 m v 2 , . 5 m h 2 = . 5 m v 2 ∗ . 5 = . 5 E