Question

A flare is launched from a life raft with an initial velocity of 192 ft/sec. How many seconds will it take for the flare to return to the sea if h=192t-16t^2h=192t−16t 2 represents the height of the flare in feet above the sea tt sec after it is launched?

Answer 1

12 seconds

Explanation:

The given function is

`h=192t-16t^2`

where h represents the height of the flare in feet above the sea t sec after it is launched.

We need to find the time taken by flare to return to the sea. At sec level the height of flare is 0.

Substitute h=0 in the given function.

`0=192t-16t^2`

`0=16t(12-t)`

Using zero product property we get

`16t=0\Rightarrow t=0`

`(12-t)=0\Rightarrow t=12`

It means at t=0 and t=12 the flare is at sea level.

The time taken by flare to return to the sea is

`12-0=12`

Therefore, the time taken by flare to return to the sea is 12 seconds.