two planes are 7700 miles apart, and their speeds differ by 300 mph. They travel toward each other and meet in 7 hours. Find the speed of the slower plane.

Question

jamesj · Answer

So let's say one plane is travelling west to east with speed X
then the other plane is travelling east to west with speed X+300

But note that the plane travelling east to west is moving 'backwards' along the east-west axis.

Let's make the east-west axis the X-axis.

Suppose the first plane (west -> east) starts at the origin.  What is it's position at time t?

anonymous · Answer

I honestly have NO idea... I'm so bad at math :/ Um... 300? plus x?

jamesj · Answer

If you were driving a car at 50 mph, what would your position be at time t?

jamesj · Answer

That is, how far would you have travelled in t hours?

jamesj · Answer

still there?

anonymous · Answer

I got 400 mph !

anonymous · Answer

that's correct right?

jamesj · Answer

Yes, it is.  How'd you get that answer?