Question

A competitive diver executes a double somersault with a twist from a platform. Her height above the water t seconds after leaving the board is given in feet by h = − 16 t 2 + 0 t + 16 How long does she have to complete her somersault before entering the water?

Answer 1

One second

Step-by-step explanation:

Her height above water as function of time after leaving the board is:

`h(t)=-16t^2 +0t+ 16`

When she enters the water the height above the board is zero so h(t)=0, using that on (1):

`0=-16t^2 +0t+ 16`

solving equation for t:

`16t^2=16`

`t^2=1`

`t=√(1)=1`s

Mathematically there're in fact two possible values for t, -1 and 1 but because we're talking of time negative sign has no physical sense then we only use 1.