Question

A soccer ball is projected at an angle of 60° from the ground.It attains its maximum height in 10s. Considering acceleration due to gravity as g = 10 m/s^2. What is the velocity with which it was projected?

(a) 115.5 m/s

(b) 117 m/s

(c) 120 m/s

(d) 11.55 m/s

This question was addressed to me in unit test.

This intriguing question comes from Simple Projectile Motion topic in chapter Motion in a Plane of Physics – Class 11

Answer 1

The correct option is (a) 115.5 m/s

Explanation: The time for achieving the maximum height is equal to half of the time of flight. Therefore, the time of flight is 20s. The formula for time of flight is t = 2(v sinθ/g). Here, t = 20, θ = 60°, g = 10. Hence, on solving we will get the initial velocity as 115.5m/s.