### Home > APCALC > Chapter 5 > Lesson 5.1.3 > Problem 5-29

5-29.

Kwok is standing on top of a 160-foot tall building and throws a tennis ball straight up with an initial velocity of 24 ft/sec. Homework Help ✎

*h*(*t*) = −16*t*^{2} + *v*_{0}*t* + *s*_{0}

How far up does the tennis ball go before it turns around and starts to come down?

The tennis ball turns around when

*v*(*t*) = 0.How fast is it going when it hits the ground below?

Evaluate

*v*(time of impact). Let*h*(*t*) = 0 to find the time of impact.