Hello everyone. I was reading through quite an old textbook, 1920's, and the book mentions 'leverage' and 'moment of gravity. Specifically: there are two booms OA and OB joined at one end O, making a 'v' shape. The point O is fixed, but the booms can rotate about that point O in the horizontal plane. There is a weight W on OA, and a spring attached to OB and some fixed point above it. Now, the author says that if the weight is slightly depressed, the moment of gravity about O hardly changes, but the leverage about O of B is decrease, and a restoring force is brought into play. What does this all mean? I think 'moment of gravity' has something to do with torque, but what on earth does he mean by 'leverage'? Any help is appreciated.