Asking my birth father for money

Hi, Firstly please don't attack me I understand that this can be a touchy subject. I'm 19 and I'm going to University in England with the help of many loans to pay for tuition. My adoptive parents have always been very generous with me and very helpful, but they don't have the money to keep giving to me. I'm unable to get a job as my course is very demanding and I have little to no free time. I do however have a full-time job whenever I am on the holidays. Christmas/Summer. I don't go out partying or drinking or taking drugs, I don't need money for any of that, I just need a little extra cash to buy study books and food. I was wondering if I could ask my birth father for money, I've talked to him through facebook a couple of times but I've never met up with him. I didn't even know he was my dad until about a year ago. He has 4 other children from different women whom he has never met up with and only stayed in contact with online, he didn't seem surprised to know that I was his biological daughter. He has told me that his other daughter asks for money and I guess that's where I kind of got the idea from. I don't want to seem rude, but I'm very low on funds right now, I've been selling my clothes and old textbooks etc. online but it just doesn't seem to cut the costs of living in London. I was adopted when I was 10 and my biological dad never had to pay child support or anything like that during the 10 years that I was living with my biological mother and in foster care, obviously I know that's not an excuse for wanting money from him, but he's really never had to give me anything. Please let me know what I should do!