Question

A particle at the top of a tower of height 30m from ground is thrown in the vertically
upward direction with a speed of 20m/s. The maximum height achieved by the particle
from the ground is H. Then the value of H/10 is (g = 10 m/s)
​

Answer 1

Well, nothing to fear in this question. Proceed forward without any immense fear and see answer is coming out.

Assume the particle to be a perfectly shaped ball. Then, it would become more logical to you. On doing such, if we proceed, so we have to proceed as under :

The ball is actually thrown vertically upwards.

Given, Initial velocity with which the ball is thrown (u) = 20 m/s.

Maximum height achieved = H

Also, at the highest point of reach , final velocity (v) = 0.

Acceleration will be negative and will of course due to gravity. So, acceleration (a) = - g ( negative acceleration due to gravity) = - 10 m/s²

By applying the equation of motion,

v² - u² = 2 g H

Or, (0)² - (20)² = 2 (- 10) (H)

Or, - 400 = - 20 H

Or, H = 400/20

Or, H = 20

So, the value of H/10 = 20/10 = 2 m.