Is this the right equation to use?

[magnifik]

Homework Statement

A cannon ball is fired with speed v0 at an angle phi above the horizontal. The launch point is at height h above the ground. Find the time to hit the ground, and the magnitude of the velocity when the ball hits the ground (in terms of v0, g, h, \phi)

Homework Equations

y=v0sin(\phi)t - 1/2gt^2
vy=v0sin(\phi) - gt

The Attempt at a Solution

how do i account for initial height?

 

[rock.freak667]

Homework Equations

y=v0sin(\phi)t - 1/2gt^2
vy=v0sin(\phi) - gt

The Attempt at a Solution

how do i account for initial height?

y=y₀+v₀sin(φ)t - 1/2gt²