An alert physics student stands beside the tracks as a train rolls slowly past. He notes that the frequency of the train whistle is 493 Hz when the train is approaching him and 476 Hz when the train is receding from him. Using these frequencies, he calculates the speed of the train. What value does he find

An ambulance emits a frequency of 450 hz from its siren. what frequency is heard by a man as the ambulance moves toward him? less than 450 hz more than 450 hz 450 hz 0 hz

Which of the following is considered to be a vector?               a.  temperature    b.  velocity    c.  time    d.  mass

This chart shows characteristics of three different types of waves. which statement is best supported by the information in the chart? wave x and wave y are mechanical waves, and wave z is an electromagnetic wave. wave x and wave y are electromagnetic waves, and wave z is a mechanical wave. wave x and wave z are electromagnetic waves, and wave y is a mechanical wave. wave x and wave z are mechanical waves, and wave y is an electromagnetic wave.