Question

An object is launched upward with an initial velocity of 64 feet per second from a platform 80 feet high.

1.) Write a height model for the object.
I wrote my model as .... h=-16t^2 +64t +80

2.) How many seconds until the maximum height is reached?
I had 2 seconds as my answer but now I'm doing this irrelevant work and its confusing me


3.) What will be the maximum height?


4.)How many seconds until the object hits the ground?

Answer 1

I need help asap. thx

Answer 2

t=2 is the correct time.
So, plug in t=2 for your formula for h to get the max height.

to see when it hits the ground, just set h=0:

-16t^2+64t+80 = 0
-16(t+1)(t-5) = 0
so, h=0 at t=5