Question

A projectile if fired straight upward with an initial velocity of 400 feet per second. The height of the projectile, h(t), if represented by the function h(t) = -16t2 + 400t, where t is the time in seconds.

How long does it take the projectile to reach the maximum height?


2500 seconds


12.5 seconds


25 seconds


6.25 seconds

Answer 1

@989freak

Answer 2

im horibble at math

Answer 3

oh god..

Answer 4

@Cosmichaotic

Answer 5

@triciaal

Answer 6

:(

Answer 7

Ok, first, do you know how to determine the maximum for the equation?

Answer 8

It's going to involve h'(t).

Answer 9

ok ok , my answer, I got C

Answer 10

Hmm...that's not what I got. First we have the height as: \[h(t) = -16t2 + 400t\] Taking the derivative gives us: \[h'(t) = -32t + 400\] The projectile will peak when the slope for the equation is equal to zero, so set the derivative (which is the slope) = 0. That gives me: \[32t = 400\] I think you can take it from here, but I'm pretty sure now that it's not C.