Math 2 Word Problem

Question

If a toy rocket is launched vertically upward from ground level with an initial velocity of 148 feet per second, then its height h after t seconds is given by the equation h(t)=-16t2+148t. How long will it take the rocket to return to the ground?

Please explain the answer!

Answer 1

Set h(t)=0 and solve for t

Obviously t=0 which means the rocket was launched at time 0 from ground level.

The other root is t= 9.25 sec. which is when the rocket will again have 0 altitude, i.e. hit the ground.