A batter hits a baseball upward with an initial speed of 96 feet per second. After how many seconds does the ball hit the ground? Use the formula h = rt − 16t2 where h represents height in feet and r represents the rate in feet per second.

Question

anonymous · Answer

You need an angle.  You mean straight up?

anonymous · Answer

Its vertical motion

parthkohli · Answer

When the ball is at the ground, the height is $0$.
Replace $h = 0$.

$ \color{Black}{\Rightarrow 0 = 96t - 16t^2 }$

hba · Answer

The ball hits the ground after 6 seconds.

hba · Answer

0 = 96ft/s * t - 16 t^2

16t^2 = 96t
16t = 96
t = 96/16 = 6

parthkohli · Answer

$0 = 16t(6 - t)$
$0 = 6 - t$

Solve the rest.

anonymous · Answer

@ParthKohli how do i solve the rest?

parthkohli · Answer

• Subtract 6 from both sides.
• Multiply both sides by -1.

anonymous · Answer

so the answer is 6?

parthkohli · Answer

Yeah!

anonymous · Answer

okay thanks!

parthkohli · Answer

You're welcome, Megan O:)