If a ball is thrown vertically upward with a velocity of 80 fts, then its height after seconds is . (a) What is the maximum height reached by the ball? (b) What is the velocity of the ball when it is 96 ft above the ground on its way up? On its way down?

If a rock is thrown upward on the planet mars with a velocity of 10 mys, its height in meters t seconds later is given by y − 10t 2 1.86t 2 . (a) find the average velocity over the given time intervals: (i) [1, 2] (ii) [1, 1.5] (iii) [1, 1.1] (iv) [1, 1.01] (v) [1, 1.001] (b) estimate the instantaneous velocity when t − 1.