A 1.57 kg brick measures 20.0 cm x 8.00 cm x 5.50 cm. Taking the zero of potential energy when the brick lies on its broadest face. (a) What is the potential energy when the brick is standing on end? Note: You can treat the brick as though all its mass is concentrated at its center. (b) What is the potential energy when it's balanced on its 8 cm edge?
The Attempt at a Solution
I could not figure out the first part of the question because I don't know what "standing on end" means.
As for B:
m = 1.57 kg
g = 9.81
h = 0.08 m
Ug = (1.57)(9.81)(0.08) = 1.23 J
That is the answer I get, but Mastering Physics tells me that there was a rounding error and the answer is 1.17 J and I cannot figure out where I was wrong. This is not supposed to be a hard problem. Maybe I'm thinking too hard about it??