Question

Two jets leave an airport at the same time, flying in opposite directions. The first jet is traveling at three hundred seventy-seven mph and the other at two hundred seventy-five mph. How long will it take for the jets to be 9128 miles apart?

Answer 1

Remember that distance equals speed times time:
`d=st`. We know for our problem that the speed of our first jet is 377 mph, so
`s_(1)=377`. We also know the speed of our second one is 275 mph, so
`s_(2)=275`. Since the the time that will it take for the jets to be 9128 miles apart is the same,
`t` is going to be equal for both jets. Now we can setup our distance equations for both jets.
For our first jet:

`d_(1)=377t`
For our second jet:

`d_(2)=275t`

We know for our problem that after
`t` the jets will be 9128 miles apart, so the total distance will be 9128:
`d_(t)=9128`. Since our jets are traveling in opposite directions, the distance between them will increase over time, so we are going to add
`d_(1)` and
`d_(2)`, and set them equal to
`d_(t)` to find our time:

`d_(t)=d_(1)+d_(2)`

`9128=377t+275t`

`9128=652t`

`t= (9128)/(652)`

`t=14`

We can conclude that our jets will be 9128 miles apart after 14 hours.