Question

A projectile is thrown in the upward direction making an angle of 60 with the horizontal direction with a velocity of 147 ms–1. Then the time after which is inclination with the horizontal is 45, is

(a) 15 (√3- 1)*

(b) 15 (√3 + 1)*

(c) 7.5 (√3 - 1)*

(d) 7.5 (√3 + 1)*

Answer 1

Correct option: (c) 7.5 (√3 - 1)s

Explanation:

At the two points of the trajectory during projectile motion, the horizontal component of the velocity is same. Then u cos 60 = v cos 45