I know that normal force usually equals mg on a flat surface. but how do i find Fn on a slanted surface? And also, how do i make superscripts and subscripts with alt codes (windows 7)? Also, is ma=mg i know that a=acceleration, and that's usually because of gravity. But in the book i'm reading (physics for dummies), it gives me a long example for finding vectors and comes to the conclusion that: a=g sin [tex]\theta[/tex] this is one of my first posts, cool website, im thankful i joined. thank you for the help. One last thing, I will probably be having more problems like this involving what im reading from my book. I was wondering if there was someone (you) that i could just email directly about problems (just for the sake of saving time).