An alert physics student stands beside the tracks as a train rolls slowly past. He notes that the frequency of the train whistle is 441 Hz when the train is approaching him and 422 Hz when the train is receding from him. Using these frequencies, he calculates the speed of the train. What value does he find

Dao makes a table to identify the variables used in the equations for centripetal acceleration. what quantities belong in cells x and y?

Ahorizontal force of 400.0 n is required to pull a 1760 n truck across the floor at a constant speed. find the coefficient of sliding friction.

Global warming will produce rising sea levels partly due to melting ice caps but also due to the expansion of water as average ocean temperatures rise. to get some idea of the size of this effect, calculate the change in length (in m) of a column of water 1.45 km high for a temperature increase of 1.12°c. assume the column is not free to expand sideways. as a model of the ocean, that is a reasonable approximation, as only parts of the ocean very close to