Question

Two planes start from the same point and fly in opposite directions. The first plane is flying 60 mph slower than the second plane. In 2.5 h, the planes are 1625 mi apart. Find the rate of each plane.

Answer 1

The first plane is moving at 295 mph and the second plane is moving at 355mph.

Explanation:

In order to find the speed of each plane we first need to know the relative speed between them, since they are flying in oposite directions their relative speed is the sum of their individual speeds. In this case the speed of the first plane will be "x" and the second plane will be "y". So we have:

x = y - 60

relative speed = x + y = (y - 60) + y = 2*y - 60

We can now apply the formula for average speed in order to solve for "y", we have:

average speed = distance/time

average speed = 1625/2.5 = 650 mph

In this case the average speed is equal to their relative speed, so we have:

2*y - 60 = 650

2*y = 650 + 60

2*y = 710

y = 710/2 = 355 mph

We can now solve for "x", we have:

x = 355 - 60 = 295 mph

The first plane is moving at 295 mph and the second plane is moving at 355mph.