F.5 phy
2008-04-13 9:04 pm
A motor car of mass 2500kg accelerates from rest to a speed of 20 ms-1 in 5s on a level road . Find the average power of the car.
回答 (1)
2008-04-13 9:09 pm
✔ 最佳答案
power = energy / time.kinetic energy gained : 0.5mv^2 - 0.5mu^2
= 0.5 (2500) (20)^2 - 0.5 (2500) (0)^2
= 500000J
=500KJ
average power of the car : 500KJ / 5S
= 100000W
= 100KW
參考: me
收錄日期: 2021-04-14 19:06:41
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20080413000051KK01155