Originally Posted by

**vesperka** I have to answer a problem using the following function:

-16t^2 + Vot + So

(Sorry the notation is bad, but the middle term is initial velocity and So is distance)

The question: A ball is thrown straight down from the top of a 220ft building with an initial velocity of -22 feet per second. What is its velocity after 3 seconds? What is its velocity after falling 108 feet?

I can get the first part of the problem. I found the derivative to be V=-32t-22, so i plugged in 3 and got -118ft/s, easy enough.

However, I don't know how to find the velocity after 108 feet. I remember I'm supposed to say that the ball is 112 feet from the ground instead of saying it fell 108 feet, but whenever I try to solve it seems like I have too many unknown variables. Any hints?