One end of a taut rope is fixed to a post. What type of wave is demonstrated if the free end is quickly raised and lowered

When you push downward on a book at rest on a table, you feel an upward force. does this force depend on friction? defend your answer.

Aplane flying horizontally at an altitude of 1 mile and a speed of of 500mih passes directly over a radar station. find the rate at which the distance from the plane to the station is increasing when it is 2mi away from the station.

Which of these is constant for all types of electromagnetic radiation in a vacuum? select one: a. wavelength b. frequency c. photon energy d. amplitude e. velocity