Is the bending of waves when they enter a new medium at an angle

Consider a system with two masses that are moving away from each other. why will the kinetic energy differ if the frame of reference is a stationary observer or one of the masses?

What is the increase in density of a medium due to wave travel?

Four 5-gram blocks of metal are sitting out in the sun and absorb the same amount of heat energy. use the following specific heat capacity data to determine which block will increase its temperature the most.