A crew working with dynamite to clear a road blasted a large rock straight up with
an initial velocity of 140 ft/sec. The rock reaches a height of s(t) = -16t^2 +
140t after t seconds
a) What is the velocity of the rock att seconds?
(1)
b) What is the velocity of the rock after when it is 170 feet above the ground on the
way up?
(t) = 170
c) What is the velocity of the rock when it is again at 170 feet on the way down?
d) When does the rock hit the ground?
e) What is the velocity when it hits the ground?