Use a (t) = - 32 feet per second per second as the acceleration due to gravity. (Neglect air resistance.) - With what initial velocity must an object be thrown upward (from ground level) to reach the top of the Washington Monument (approximately 550 feet) ?

a = - 32 ft/s²

h = 550 ft

Let the initial velocity is u. The velocity at maximum height is zero.

use third equation of motion

v² = u² + 2 a h

0 = u² - 2 x 32 x 550

u² = 35200

u = 187.62 ft/s

u = 187.61 ft/s

Explanation:

Given that

g = - 32 ft/s²

The maximum height, h = 550 ft

Lets take the initial velocity = u ft/s

We know that

v²=u² + 2 g s

v=final speed, u=initial speed, s=height

When the object reach at the maximum height then the final speed of the object will become zero.

That is why

u² = 2 x 32 x 550

u² = 35200

u = 187.61 ft/s

That is why the initial speed will be 187.61 ft/s