A small ball moves on a circular orbit with a circumference of 2m, starts from a certain point, and goes back to the point, then the ball's_______
A. The displacement size is 0 and the distance is 2m
B. Displacement size and distance are both 2m
C. The displacement size is 2m, and the distance is 0
D. Displacement size and distance are both 0
Answer:A
A small ball moves on a circular orbit with a circumference of 2m, starts from a certain point, and goes back to the point, then the ball's_______
A. The displacement size is 0 and the distance is 2m B. Displacement size and distance are both 2m C. The displacement size is 2m, and the distance is 0 D. Displacement size and distance are both 0