Question

A projectile is 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?



25 sec


6.25 sec


12.5 sec


2500 sec

Answer 1

Usually, all we need is the initial angle, and initial speed. (With the assumption that air resistance/friction should be ignored).

But, you are already given the function, so we don't have to derive it.

Answer 2

The maximum height is reached when the velocity is 0.

Answer 3

um check ur messages i explained it over there, it's easier for me

Answer 4

So, you can either do it through calculus -
find the derivative h'(t), and set h'(t)=0 to solve for the time when the maximum is reached;

or, through algebra -
find the vertex if you want to do it algebraically, and the y-value of the vertex is the maximum height)

Answer 5

can you do this problem ?