A train starts from rest at a station and accelerates uniformly at 0.5 m/s^2 until it reaches a speed of 90km/h
a) How long does the train take to reach this speed?
b) How far doess the train travel in reaching this speed?
maths
2007-11-20 4:53 am
回答 (2)
2007-11-20 5:02 am
✔ 最佳答案
a) 90km/h = 25m/sBy v = u + at,
25 = 0 + ( 0. 5 )( t )
t = 50
So 50s is needed.
b) s = ut + at^2 / 2
= ( 0 )( 50 ) + ( 0. 5 )( 50 )^2 / 2
= 625m
參考: My Maths Knowledge
2007-11-21 3:15 am
都唔系maths題，係physics啊!
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