Hi Aji. I'll do the best I can, but you'll have to wait a few hours for the experts. They're all asleep at the moment.

bow, meaning to bend at the hips, is pronounced like cow, how and now.
bow, meaning the tool used in archery, is pronounced like no, tow, flow and blow.
bow, meaning the shape made by tying ribbon or string a certain way, is also pronounced like no.

And just to confuse things,

bough, meaning a branch of a tree, is pronounced like cow.

Hope that helps.

edit: I may have been first bellig'y, but I like your explanation better.