How do I explain to my dad that at my age having an internet filter is

Be patient with your dad. The internet is still wild and crazy. He's mostly right and that's enough because he loves you. Just keep on showing responsibility.

Your father has it on there for a reason. Your age and grades have nothing to do with it. There are things out there that you don't need to see, apparently you want to. We have our computer filtered and password protected to protect our children and believe or not, we don't want or need to see the garbage that is on the internet.

Homework is a different thing entirely. But I am sure you can leave the filters on and have your own password so you can do your homework. Instead of getting upset and yelling about it, approach him in a respectful manner and ask nicely if he can do something so that you can do your school work without having to ask him the password all the time. If he is reasonable, he will do something, if he doesn't, ask why, he may tell you.