If a rock is thrown upward on the planet Mars, its height in meters t seconds later is given by f(t) = 10t - 2t2.
a. Find the average velocity from t = 1 to t = 2 seconds.
b. Using the definition of the derivative, find the instantaneous velocity of the rock when t = 1.
c. When does the rock hit the ground?
d. How fast is the rock traveling when it hits the ground?