Question

A stone is projected vertically upward with a
speed 30 m/s from the top of a tower. If it strikes
the ground with a speed of 10 √3 m/s, then height
of tower is (g = 10 m/s)
(1) 10 m
(2) 15 m
(3) 30 m
(4) 20 m​

Answer 1

Answer:

30m

Explanation:

When the body is projected from the building it will go with v=30m/s. So naturally it will reach the same height with the same speed. (V=U) ...... Now it will travel all the way down the tower and we have to calculate the height of the tower..... Here you go

V² = u² + 2aS

V² = u² - 2gh

2gh= (30) ² - (10√3)²

....

Like that you get h=30m