# Rapid physics

**Classical Mechanics**Level 1

Rapids in rivers occur when the river narrows. Consider a simple river where the cross-section can be modeled as a rectangle 60 m wide and 2 m deep. If the speed of the river water at this point is 1 m/s, what would be the speed of the water **in m/s** at a point further down where the river narrows to be 10 m wide (but is still 2 m deep)?

**Details and assumptions**

- Assume the height of the river does not change appreciably.