1988 Buick Century Why is my car making a whining noise?

Hi, My daughters car started making a whining noise when we accelerate. Once we get up to speed (55) the noise goes away. We checked all the fluids and they are fine. When we idle you can hear a grinding type noise coming from where the belt is. Almost like a bearing noise. My husband thinks it might be the power steering unit or the alternator? You can also hear the belt making a squeaking noise when we idle too. The car runs fine and shifts fine.