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

The free body diagram shows a box being pulled to the left up a 25-degree incline. the magnitude of the normal force is

Two objects of different mass start from rest, are pulled by the same magnitude net force, and are moved through the same distance. the work done on object 1 is 900 j. after the force has pulled each object, object 1 moves twice as fast as object 2. how much work is done on object 2?

An engine undergoes a cycle as shown in the diagram. during a complete cycle the work done by the gas is 28.5×103 j and the energy transferred thermally out is 99.4×103 j. there are 1.5×1024 gas molecules and they have three active degrees of freedom. 6. (6 pts) during which process(es) is energy transferred thermally into the gas? a. 1→2 b. 2→3 c. 4→1 d. 1→2 and 4→1 e. none of the above