Question

A block of cheese is thrown upward on the moon with an initial velocity of 15 m/s, and it's height at time t is given by the equation h(t)=15t-0.8t^2

find the average velocity for the time period beginning when t=6 and lasting for 1) 0.2 seconds 2) 0.1 seconds 3) 0.05 seconds 4) 0.01 seconds