Ahelicopter lifts a 60 kg astronaut 17 m vertically from the ocean by means of a cable. the acceleration of the astronaut is g/10. (a) how much work is done on the astronaut by the force from the helicopter? j (b) how much work is done on the astronaut by her weight? j (c) what is the kinetic energy? j (d) what is the speed of the astronaut just before she reaches the helicopter?

Amerry-go-round of radius r, shown in the figure, is rotating at constant angular speed. the friction in its bearings is so small that it can be ignored. a sandbag of mass m is dropped onto the merry-go-round, at a position designated by r. the sandbag does not slip or roll upon contact with the merry-go-round. how would you rank the following different combinations of m and r on the basis of the angular speed of the merry-go-round after the sandbag "sticks" to the merry-go-round from largest to smallest. a) m = 10kg, r = 0.25r b) m = 20kg, r = 0.25r c) m = 10kg, r = 0.50r d) m = 10kg, r = 1.0r e) m = 15kg, r = 0.75r f) m = 40kg, r = 0.25r