Asked by dhandip

A swimmer can swim in stillwater at a rate 4 kilometre per hour. If he swims in a river flowing at 3 kilometre per hour and keeps his direction with respect to water perpendicular to the current,find his velocity city with respect to the ground
Answered by Damon
say the water is moving in x direction at 4 km/h
say we swim in y direction at 3 km/h

then our speed is sqrt (3^2+4^2) = 5 km/h

tan angle above x axis is
tan theta = 3/4 = .75