In 1980, over San Francisco Bay, a large yo-yo was released from a crane. Suppose the yo-yo was 160 kg, and it consisted of two uniform disks of radius 34.7 cm connected by an axle of radius 3.47 cm. What was the magnitude of the acceleration of the yo-yo during (a) its fall and (b) its rise? (c) What was the tension in the cord on which it rolled?

Which statement is true? a) the work done to lift an object 6 meters is greater than the gravitational potential energy it gains. b) the work required to push an object is less than the work required to pull an object the same distance. c) the work required to raise an object to a height is equal to the gravitational potential energy the object gains. d) the work done against gravity to lift an object straight up is greater than the work required to roll it up a ramp.