### Home > AC > Chapter 10 > Lesson 10.1.4 > Problem 10-40

*h* = −16*t*^{2} + 80*t*, where *h* is the height measured in feet and *t* is the time measured in seconds.

When does the ball land on the ground?

Substitute

for to find how long it takes for the ball to land on the ground.Solve by factoring.

represents when the ball was on the ground before it started flight; therefore, it took seconds for it to land after its flight.

What is the maximum height of the ball during its flight?

Assume that the ball would be highest exactly halfway through its flight.

Knowing this information, substitute half of the total time it took the ball to land forand solve for.

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