A juggler throws a ball into the air from a height of 5 ft with an initial vertical velocity of 16 ft/s. The function that models the height h of the ball in feet t seconds after the ball is thrown is h(t) = -16t2 + 16t + 5. How long does the juggler have to catch the ball before it hits the ground? _______ s.

Question

imstuck · Answer

Solve this by factoring it.  When h = 0, the ball is at the ground.  So you have to find where the function = 0 in order to find out how long he has before the ball hits the ground.  When you solve a quadratic formula by factoring, you are in actuality finding where the function = 0, and that's what we are looking for here:  the time it will take for the height of the ball to be 0.

imstuck · Answer

So let's factor!

imstuck · Answer

I'm assuming you are familiar with the quadratic formula?

anonymous · Answer

-(4t-5)(4t+1)=0

imstuck · Answer

That's right!  Which one of those is your solution, then?  Remember that time cannot be a negative number.

anonymous · Answer

zero is -1.5 and 1.5 so answer is 1.5?

imstuck · Answer

Actually, it's this...follow me for a sec...

anonymous · Answer

no 1.45
sorry

anonymous · Answer

made a mistake

imstuck · Answer

(4t - 5) = 0...4t = 5...t = 5/4...t = 1.25 seconds (not 1.5)

anonymous · Answer

tq

imstuck · Answer

is that a "ty"?  I think it is!  You're welcome!  Thank you for the medal!