Question

Suppose n(t) = -51^2 + 10t + 3 represents the height of a

diver above the water (in meters), 1 seconds after

the diver leaves the springboard. Which of these

statements is true?

(А)

After 1 second, the diver will be 3 feet above

the water.

B

After 5 seconds, the diver will be 25 feet above

the water.

С

After 1 second, the diver will be 8 feet above

the water.

D

After 5 seconds, the diver will be 78 feet above

the water.

Answer 1

The correct option is (c).

Explanation:

The height of a diver abov the water is given by :

`h(t) = -5t^2 + 10t + 3` ....(1)

Where h(t) is in meters and t is in seconds

Put t = 1 s, in equation (1) we get :

`h(1) = -5(1)^2 + 10(1) + 3\\\\=8\ \text{feet}`

Put t = 5 s, in equation (1) we get :

`h(1) = -5(5)^2 + 10(5) + 3\\\\=-72\ \text{feet}`

Out of the given options, "after 1 second, the diver will be 8 feet above the water is (c)". Hence, the correct option is (c).