Quiz – Relative Motion – Crossing a River

A hiker travelling West comes to a river that flows South. The hiker wants to swim straight West across the river. If they can swim at a rate of 0.60 m/s and the river has a speed of 0.25 m/s and a width of 78 m, how long will it take them to cross the river? Answer in the form '28 s'.

A hiker travelling South comes to a river that flows East. The hiker swims straight South across the river. If they swim at a rate of 0.80 m/s and the river has a speed of 0.15 m/s, what is their resulting velocity? Answer in the form '3.2 m/s [28 N of W]'.

A hiker travelling West comes to a river that flows South. The hiker swims straight West across the river. If they swim at a rate of 0.55 m/s and the river has a speed of 0.15 m/s and a width of 58 m, how far downstream do they end up? Answer in the form '1.2 m'.

A hiker travelling North comes to a river that flows East. The hiker wants to swim straight North across the river. If they can swim at a rate of 0.35 m/s and the river has a speed of 0.10 m/s, what direction should they swim? Answer in the form '28 N of W'.