A projectile is projected from the ground with speed 25 m/s. Its speed at the highest point is 15 m/s. Neglect air resistance and take g = 10 m/s². The maximum height reached by it is:
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Question

A projectile is projected from the ground with speed 25 m/s. Its speed at the highest point is 15 m/s. Neglect air resistance and take g = 10 m/s². The maximum height reached by it is:

G1 Physics · Accepted Answer

At the highest point only the horizontal component remains, so uₓ = 15 m/s. Initial vertical component satisfies u² = uₓ² + uᵧ²: 25² = 15² + uᵧ² ⇒ uᵧ = 20 m/s. Maximum height H = uᵧ²/(2g) = 400/20 = 20 m. Therefore option C is correct.