Mathematics

Relative Speed Same Direction

Find relative speed when two objects move in the same direction.

Relative Speed = |u - v|

Formula Explanation

The faster object gains on the slower one at the difference of their speeds.

Variables Explained

u, v = speeds of the two objects.

Solved Example

A car moves at 60 km/h and another at 40 km/h in same direction. Relative speed?
Relative speed = 60 - 40 = 20 km/h.

Exam Tip

Use absolute value so the result is positive.