Question

The function h defined by h (t) = 4.9 (10+t) (10 - t) models the height, in meters, of an object t seconds after it is dropped from a

helicopter

Answer 1

(a) 10 seconds

(b) 490 meters

Explanation:

(A)

When the object hits the ground, it shows that the height is 0. Hence, h(t) = 0.

0 = 4.9(10+t)(10-t)

0 = (10+t)(10-t)

t = 10, -10

Since time cannot be negative, t = -10 will be rejected.

Therefore, t = 10 seconds

(B)

Based on the question, "t seconds after the object is dropped from a helicopter", means that the time starts right after the object is dropped from the helicopter, this shows that t = 0.

h(0) = 4.9(10+0)(10-0)

= 4.9(100)

= 490 meters