A ball is thrown into the air with an upward velocity of 28 ft/s. Its height in feet after t seconds is given by the function h = -16t2 + 28t + 10. In how many seconds does it take the ball to reach its maximum height?

Question

A ball is thrown into the air with an upward velocity of 28 ft/s.  Its height in feet after t seconds is given by the function h =  -16t2 + 28t + 10.  In how many seconds does it take the ball to reach its maximum height?

tkhunny · Answer

This is a standard model.  You are expected to know WHEN the maximum value will be achieved and be able to solve for the maximum value.

You have a choice.  Complete the Square and put this thing in Vertex Form or you may already know the secret...  Heard of -b/(2a)?

tkhunny · Answer

Answer the questions this time.  Don't just repost with no work shown.

anonymous · Answer

i just need to know how to work it out

tkhunny · Answer

Perfect.  Now, answer my question.  Make your choice.

anonymous · Answer

i don't know either way

tkhunny · Answer

Can you solve this: -16t2 + 28t + 10 = 0?

tkhunny · Answer

This is a deficiency.  You should know about Completing the Square before you see a problem like this.  Someone messed you up by giving you a problem without giving you the proper tools.  Let's see if we can get you through this one.

anonymous · Answer

ok thanks

tkhunny · Answer

Well, answer my new question.  Can you solve that Quadratic Equation?