Calculus ?

Question

𝑠(𝑡) = −16𝑡^2 + 64𝑡 + 100 

A. Determine the tomato’s average velocity over the interval [𝑎, 𝑎 + ℎ] (i.e., from 𝑡 = 𝑎 to 𝑡 = 𝑎 + ℎ).

Simplify your answer completely.

I keep getting 8a+4h-16 as my final answer

Update:

Use your answer from Part A to determine the tomato’s average velocity over the interval [3,3.1].

Update 2:

When will the tomato hit the ground?