Question

A projectile is projected with kinetic energy K, it has the maximum possible horizontal range, then its kinetic energy at the highest point will be

(a) 0.25 K 

(b) 0.5 K 

(c) 0.75 K 

(d) K.

Answer 1

Answer is (b) 0.5 K

Since range is maximum therefore θ = 45°, hence v_x = ν cos45° = ν/√2.

At the highest point the net velocity of the projectile is ν_x.