How many times should the initial speed of the body thrown at the top be increased so that the height

How many times should the initial speed of the body thrown at the top be increased so that the height to which it rises would increase by 4 times?

The height of a horizontally thrown (shot) body is calculated by the formula:

hmax = v² / (2 * g).

Achieved at speed:

v = √ (2 * g * hmax).

In order for the height to rise to the highest point of the trajectory to be four times greater, it will be necessary to increase the speed to:

4 * hmax = v² / (2 * g),

v = 2 * √ (2 * g * hmax), i.e. twice.

Answer: the initial speed should be doubled.