River crossing: shortest time vs shortest path

A boat crosses a flowing river. Choose the heading angle: aim straight across for minimum time (drift downstream) or upstream at the right angle to land directly opposite; see resultant velocity, time, drift and the impossible case v_boat < v_river.

About this experiment

What you do in the lab

Change the controls and watch the physics behave in real time in 3D. Live readouts and graphs show the numbers behind it, and the Learn tab has the theory, procedure, observations and viva questions. Works on a phone or a laptop, in English and Hindi.

Topics: relative velocity · river boat · drift · shortest path · vectors

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