The gravitational energy of a swimmer on a driving board at different heights is shown in the table below. What is the driver's gravitational energy at 5m high? (A) 5500 J (B) 2750 J (C) 8800 J (D) 3300 J

The motor m applies a time-varying force of f (200 t) n, where t is in seconds. box b with mass 200 kg starts from rest, and the coefficients of kinetic and static friction are 0.2 and us 0.3 the acceleration due to gravity is g 9.8 m/s2 b 300 a) find the time ' when the box starts to move. b) calculate the speed of the crate at 3 s c) calculate the power delivered by the motor at t 3 s