Hello, Truthbetold!

With regards to a shot of lava at a point 1900 ft shooting straight into the air,

what was the lava's exit velocity in feet per second? in miles per hour?

Hint: If is the exit velocity of a particle of lava,

its height seconds later will be: . feet.

Begin by finding the time at which

I assume is just another term for the first velocity. . . . . Yes!

. . . You were well on your way . . .

You found that the lava reached maximum height at: . seconds.

Then the maximum height is: . feet

But we are told that the maximum height is 1900 feet.

. . So we have: .

Got it?