You are driving your car East at a speed of 30 m/s on a road along rail tracks. A train is moving West toward you at a speed of 10 m/s. The train blows its horn producing sound of frequency of 600 Hz. (vair = 343 m/s)
What frequency of the horn do you hear in [Hz]?
Suppose you pass the locomotive while the horn is still blowing. What frequency in [Hz] do you hear then?

The difference between a red shift and a blue shift has to do with wavelength frequency. t or f

You hang a book bag on a spring scale and place the bag on a platform scale so that the platform scale reads 23.7n and the spring scale reads 13.8n. what is the magnitude of the force that earth exerts on the bag?

The earth's magnetic field, with a magnetic dipole moment of 8.0×1022am2, is generated by currents within the molten iron of the earth's outer core. suppose we model the core current as a 3000-km-diameter current loop made from a 1000-km-diameter “wire.” the loop diameter is measured from the centers of this very fat wire.to decide whether this is a large or a small current density, compare it to the current density of a 7.0 a current in a 2.0-mm-diameter wire.