Question

I need to find out how long it takes him to hit the water

Answer 1

1.26

Explanation:

When he hits the water, the height will be 0. Substitute h=0.

`0 = -16t^2+2t+23`

Solve using the quadratic equation.

`x = (-b+/-√(b^2-4ac) )/(2a)`

Substitute a = -16, b=2, and c=23.

`x = (-b+/-√(b^2-4ac) )/(2a)\\\\x = (-2+/-√((-2)^2-4(-16)(23)) )/(2(-16))\\\\x = (-2+/-√(4+1472) )/(-32)\\\\x = (-2+/-√(1476) )/(-32)\\x = (-2+/-38.4)/(-32)\\x = (-2+38.4)/(-32)=(36.6)/(-32)=-1.14\\or\\x = (-2-38.4)/(-32)=(-40.4)/(-32)=1.26`

Since time in seconds must be positive then 1.26 is the solution.