Question

A stone is thrown upward from ground level. With what minimum speed should the stone be thrown so as to reach a height of 49 feet?

Answer 1

The height attained by an objects thrown from ground level is given by the equation:

$v^2=u^2-2gs$

At maximum height, v = 0, we assume $g = 32 ft/s^2$ then we have:

$0=u^2-2(32)(49)\\ \\u^2=3,136\\ \\ u= \sqrt{3,136} =56$

Therefore, the minimum speed that the stone should be thrown so as to reach a height of 49 feet is 56 feet per second.