حل !

[H.D.M]

An athlete can throw a javelin 60 m while standing, and he can run 100m at constant velocity in 10s. Neglect air resistance and the drawer height for sake of simplicity and derive an expression for the distance R in terms of initial angle and maximize it. How far can he throw the javelin while running? Compare your answer with a world-class throw of 105 m for the javelin.