Question

Two planes are 1380 miles apart and traveling toward each other. One plane is traveling

80 mph faster than the other plane. The planes pass each other in 1.5 hours. Find the
speed of each plane.

Answer 1

Answer: plane 1: 420 mph; plane 2: 500 mph

Explanation:

This is a physics exercise, but in order to solve this problem, you need to identify both planes first:

Let's call the plane 1 speed X

V1 = X

And V2 would be:

V2 = V1 + 80 = X + 80

If we combine both speeds:

V = V1 + V2 = X + X + 80 = 2X + 80

Now that we have an expression for the combined speed, let's see the rest of the data:

Distance: d = 1380 mile

Time: t = 1.5 h

We also know that the formula to get speed is:

V = d/t

We have the combined speed, so, let replace it in the above formula to solve for X:

2X + 80 = 1380/1.5

2X + 80 = 920

2X = 920 - 80

2X = 840

X = 840/2

X = V1 = 420 mph

We have V1, so to get V2:

V2 = 420 + 80 = 500 mph