A stone is projected at angle 30 ° to the horizontal. The ratio of kinetic energy of the stone at point…

A stone is projected at angle 30° to the horizontal. The ratio of kinetic energy of the stone at point of projection to its kinetic energy at the highest point of flight will be :
  1. 1 : 2
  2. 1 : 4
  3. 4 : 1
  4. 4 : 3

Solution

Let stone is projected with initial velocity v.

Kinetic energy of the stone at point of projection is KE1=12mv2.

Now, velocity of stone at maximum height is =vcos30°, so kinetic energy at that point is KE2=12mvcos30°2

Hence, the ratio KE1KE2=12mv212mvcos30°2=43

Asked in: JEE Main 2023 (29 Jan Shift 1)

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