A 1200 -kg car moves due north with a speed of 15 m/s. An identical car moves duc with the same speed . What are the direction and the magnitude of the system's total momentum ?

What is the measure of a change in an objects velocity?

By what primary heat transfer mechanism does the sun warm the earth?

Arope has one end tied to a vertical support. you hold the other end so that the rope is horizontal. if you move the end of the rope back and forth with a frequency of 4 hz, the transverse wave you produce has a wavelength of 0.5 m. what is the speed of the wave in the rope?