Describe the Doppler effect for light and what we can learn from it. What does it mean to say that radio waves are blueshifted? Why does the Doppler effect widen the spectral lines of rotating objects?

A10-kg piece of aluminum sits at the bottom of a lake, right next to a 10-kg piece of lead, which is much denser than aluminum. which one has the greater buoyant force on it? explain. b - the aluminum a) both have the same buoyant force. b) the aluminum c) the lead d) it cannot be determined without knowing their volumes.