. Consider the motion of the tip of the minute hand of a clock In one hour
A: the displacement is zero.
B: the distance covered is zero.
C: the average speed is zero.
D: the average velocity is zero.
- The starting and end points of the minute hand during a one-hour journey are the same. The distance between the starting and final positions is called displacement. As a result, its displacement during this journey is zero. Option A is the right answer.
- However, the tip of the hand has gone some distance throughout this journey, therefore the distance travelled by the tip of the hand is not zero. As a result, the average speed, which is calculated as the ratio of total distance travelled to total time taken, is not zero. Thus, options B and C are both wrong.
- Furthermore, because the average velocity is defined as the ratio of total displacement to total time taken, the average velocity of the tip stays zero. So, option D is correct.
Hence, options A and D are correct.