A roller coaster car is going over the top of a 14-m-radius circular rise. At the top of the hill, the passengers "feel light," with an apparent weight only 60 % of their true weight. How fast is the rollar coaster going?
My problem first is I am unsure where the normal force is going - my professor said that with centrifical motion the normal force is always inwards, but I remember when we did this problem he made it upwards. Then, he set mg - N = mv2/r. I just don't understand how he got the left side, why is it mg - N and not the other way around? Does it matter?
The Attempt at a Solution
N - mg = mv2/r
0.5(mg) * r = v2