What does a blue shift of the light from a star indicate?

You are traveling in a car going at a constant speed of 100km/h down a long, straight highway. you pass another car going in the same direction which is traveling at a constant speed of 80km/h. as measured from your car's reference frame this other car is traveling at −20km/h. what is the acceleration of your car as measured from the other car's reference frame? what is the acceleration of the other car as measured from your car's reference frame?

Since the energy was not raising the temperature of the water during these segments, what was the energy used to do instead? your answer must include an explanation of what is happening to the molecules.

Which two statements are true about a system? a system is a group of objects analyzed as one unit. energy that moves across system boundaries is conserved there's only one way to define the boundaries of a system all systems are made by humans