Here's a doozy for ya.

A projectile is fired directly upward with a muzzle velocity of 860 feet per second from a height of 7 feet above the ground.

A) Determine a function for the height of the projectile t seconds after it's released.

B) How long does it take the projectile to reach a height of 100 feet on its way up?

C) How long is the projectile in the air?

So far, this is what I have for A.)

X=(860cos90*) + and then I get lost. Any takers????