Question

A rocket is fired directly upwards with a velocity of 80 ft/sec. The equation for its height, H, as a function of time, t, is
given by the function
H (t) = -1612 + 80+
Find the time at which the rocket reaches its maximum height, and its maximum height.
5
a) O time =
22
sec, max height = 200 ft
b) O time = 80 sec, max height = 100 ft
5
c) O time =
2
sec, max height = 100 ft
d) O time = 5 sec, max height = 200 ft
5
e) Otime = sec, max height = 400 ft
23
Revie

Answer 1

Answer:

(c).

Step-by-step explanation:

h(t) = - 16 t² + 80 t

Coordinates of the vertex are:

t = - $\frac{80}{2(-16)}$ = $\frac{5}{2}$ = 2.5 sec.

h = - 16(2.5)² + 80(2.5) = - 100 + 200 = 100 ft.