Q. In an earthquake, it is noted that a footbridge oscillated up and down in a one loop (fundamental standing wave) pattern once every 2.8 s. What other possible resonant periods of motion are there for this bridge? What frequencies do they correspond to?
Q. Mary needs to row her boat across a 100m wide river that is flowing to the east at a speed of 1.0m/s Mary can row the boat with a speed of 2.0 m/s relative to the water.If Mary rows stright north, how far downstream will she land? Draw a picutre showing Mary's displacment due to rowing, her displacemnet due to the river's motion, and her net displacement.