Hello everybody! We are going to fight coronavirus with today’s master machinery, the sweeper!!! It was easy to build but hard to make our sweeper more efficient. The main focus us the gear combinations. If we put a large gear on the motor axle and small gear on the sweep axle, that is the most efficient way. But if we want the slowest sweep, we are going to have the large gear on the sweep axle and small gear on the motor axle. As soon as we understand the math in it, we can have the best sweeper too sweep away all the virus.