On a windless day, a sailor(m = 75 kg) decides he wants to go sailing in his sailboat (m = 300 kg). In order to move on this windless day, he decides to mount a powerful battery-operated fan (m = 20 kg) on the back of his sailboat and points the running fan at the sail. The fan can deliver air that pushes against the sail to the right with a constant force of 300 N.
- (7A) If the sailboat is at rest and if the sailor runs the fan for 10 s, what will be the velocity of the boat at the end of the 10 seconds?
- (7B) Would the sailor travel faster with the sail down or the sail up?