Question

Henry is diving off a diving board that is 7 above the water. After 2 seconds, he reaches his maximum

height of 9 above the water. What height will Henry be after 5 seconds?
(please post the solution as well)

Answer 1

44 m

Explanation:

I'll assume the 5 seconds is from the time he jumped off the board.

This means we are to calculate his height 3 seconds after dropping from the height of 9 m, since he spent 2 seconds springing up off the board from a height of 7 m to the 9 m height.

we use Newton's equation of motion.

We are given

initial velocity U at the height of 9 m = 0 m/s

acceleration due to gravity downwards g = 9.81
`m/s^(2)`

distance covered S = ?

time of fall t = 3 seconds

we use S = Ut +
`(1)/(2)`g
`t^(2)`

S = (0 x 3) +
`(1)/(2)`(9.81 x
`3^(2)`)

S = 0 + 44.145

S = 44 m