Mathematics

Upstream Speed

Find speed of boat against the current.

Upstream Speed = u - v

Formula Explanation

Stream speed is subtracted when going against the current.

Variables Explained

u = boat speed in still water; v = stream speed.

Solved Example

Boat 15 km/h, stream 5 km/h. Upstream speed?
15 - 5 = 10 km/h.

Exam Tip

Upstream speed cannot be negative; boat must be faster than stream.