## Conceptual Physics (12th Edition)

The parallelogram rule is discussed on pages 28-29, and relative velocity is discussed on page 51. Her velocity relative to the riverbank equals the vector sum of her velocity relative to the water, and the water's velocity relative to the riverbank. The two vectors are equal and oppositely directed, so her velocity relative to the riverbank will be zero. $$8 km/h - 8 km/h = 0$$