速率和平均速率
回答 (2)
2009-04-25 11:37 pm
✔ 最佳答案
速率=距離除以時間距離=時間乘速率
時間=距離除速率
km/h m/min m/s
就係咁樣黎的
速率係指一段時間為持同樣的速度而不變
如小明跑步的速度是8.33m/s
而平均速率就類似如下:
小明在頭五分鐘跑步的速度是5m/s 在後四分鐘跑步的速度是 4m/s <<呢行講既係速率
頭五分鐘所跑的距離則是5m x60 s X5 min=1500m
而後四分鐘所跑的距離是 4m x60s x 4min=960m
九分鐘所跑的距離是2460m
平均一秒跑的距離=2460除以(9乘以60)=4.555 m/s <<<<<<<<<<呢度就係平均速率
參考: me
2009-04-26 1:12 am
Speed from A to B = a km/ b hr.
Speed from B to C = c km/ d hr.
Speed from C to D = e km/ f hr.
so the AVERAGE speed from A to D = ( a + c + e)/( b + d + f),
NOT ( a/b + c/d + e/f)/3!
2009-04-25 17:15:12 補充：
In general, average speed = total distance travelled/total time taken. (If a person takes 3 hours rest, distance travelled = 0, time taken = 3)
Speed from B to C = c km/ d hr.
Speed from C to D = e km/ f hr.
so the AVERAGE speed from A to D = ( a + c + e)/( b + d + f),
NOT ( a/b + c/d + e/f)/3!
2009-04-25 17:15:12 補充：
In general, average speed = total distance travelled/total time taken. (If a person takes 3 hours rest, distance travelled = 0, time taken = 3)
收錄日期: 2021-04-25 22:39:45
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20090425000051KK01072