1st:The magnitude of average velocity of a moving object is always its average speed
2nd:The magnitude of instantaneous velocity of a moving object is its instantaneous spped
Why both statements are wrong?
mechanics
2007-02-23 2:28 am
回答 (1)
2007-02-23 2:44 am
✔ 最佳答案
1st:The magnitude of average velocity of a moving object is always its average speed2nd:The magnitude of instantaneous velocity of a moving object is its instantaneous speed
第一句)
velocity(速度)是向量。speed(速率)是無向量，兩者不相同。
例如以運動會的400m賽跑為例，
50s跑完400m，
平均速度是0，因為位移為0。
平均速率為400/50= 8ms-1
第二句)應該是正確。
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