An object dropped off a 240ft tower has a position represent

An object dropped off a 240ft tower has a position represented by the equation:

H(t) = 240 -16t²

^{a) How long would it take for the object to hit the ground?}

^{b) How fast is the object moving when it hits the ground?}

^{c) What is the average velocity during its fall?}

a) time taken by object to hit the ground.

H(t) = 0

240- 16t^2 = 0

t = sqrt (15) = 3.87 sec

b) velocity = dH/dt = -32t

t = 3.87

So velocity = 123.9 ft/sec

C) average velocity = 240/3.87 = 63.01 ft/sec