Q. A 3-m-long rigid beam with a mass 120 {rm kg} is supported at each end. An 70 {rm kg} student stands 2.0 {rm m} from support 1. How much upward force does support 1 exert on the beam?
Q. Eight books, each 9.0 cm thick with mass 1kg, lie flat on a table. How much work is required to stack them one on top of another?