A ball is thrown vertically upward in the air from the top of a cliff. Its height above the ground is approximated by the

relation h = -4t2 +32t + 80, where h is the height in metres above the ground level and t is the time in seconds. Include

a labelled diagram showing your answer.

a) How long is the ball above 80 m? Show/Explain how you know.

b) How long is the ball in the air? Show/Explain how you know.

sim51 Nov 5, 2020