Two points on a merry-go-round are located at distances from the center r1 and r2, where r1 < r2. While the merry-go-round is in the process of speeding up to operational speed, which of the follow
单选题
Two points on a merry-go-round are located at distances from the center r1 and r2, where r1 < r2. While the merry-go-round is in the process of speeding up to operational speed, which of the follow