1995 C280 Whining Noise

Hey, My Mercedes C280 makes a very loud whining noise whenever i turn it on. After driving it for a while the noise seems to go away, and it doesn't seem to harm the car. I do not have a very extensive knowledge of cars, although if anyone can help, I am sure with my basic knowledge and some research i could figure it out. My current best guess is a weak battery, which maybe is making the alternator overwork to charge it.

Please help with any suggestions. I can also help if additional information is needed.

P/S pump......bad belt......take mother in law out of trunk??:evillol: