math help plz

Question

A rocket is fired upward from a planet . the height in meter after t seconds is given by the function h(t)=-2.3t^2+41t. When will the rocket reach a height of 160 meter. When will it attain its maximum height and what is its maximum height

 

Answer 1

Set h(t) = 160 m and solve for t.

 

-2.3t² + 41t = 160

 

-2.3t² + 41t - 160 = 0

 

Solve for t and get 

 

t = 5.77 s and 12.06 s

 

It reaches 160 m in 5.77 s on the way up, and again in 12.06 s on the way down.