Question

With what initial velocity must an object be thrown upward (from ground level) to reach the top of the Washington Monument (approximately feet)?

Answer 1

`\begin{equation*} 187.62\text{ }ft\/s \end{equation*}`

Step-by-step explanation

To find the initial velocity that the object must have, we have to apply one of Newton's equations of motion:

`v^2=u^2-2gs`

where v = final velocity

u = initial velocity

g = acceleration due to gravity = 32 ft/s/s

s = distance/height traveled

Since the object reaches the top of the monument, its final velocity is 0 ft/s.

Substitute the given values into the equation and solve for u:

`\begin{gathered} 0^2=u^2-2*32*550 \\ \\ 0=u^2-35200 \\ \\ u^2=35200 \\ \\ u=√(35200) \\ \\ u=187.62\text{ }ft\/s \end{gathered}`

That is the initial velocity that the object must be thrown at.