Eg from 0s to 40s, car A speed increases uniformly from 0m/s to 20m/s.
From 40s onwards, car a travels at constant speed.
From 0s to 20s, car b speed increases uniformly from 0m/s to 15m/s .
From 20s onwards, car b travels at constant speed.
How to calculate the time when 2 cars are at the same position in a velocity time graph?
2016-04-17 3:55 am
回答 (1)
2016-04-17 5:10 am
✔ 最佳答案
Distance da covered by car A:da = 1/2Va*ta+Va*t = 10*40+20*t = 400+20t
Distance db covered by car B:
db = 1/2Vb*tb+Vb*(ta-tb+t = 7.5*20+15*(20+t) = 150+300+15t
da = db
400+20t = 450+15t
5t = 50
t = 50/5 = 10 sec
total time tx = ta+t = 40+10 = 50 sec
check
da = 400+20*10 = 600 m
db = 150+15*30 = 600 m
....it works !!!
收錄日期: 2021-05-01 20:36:48
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20160416195506AARaKmA