A train previously at rest starts accelerating. It takes 4 seconds for the first carriage to cross the reference point K. How long will it take for the 10th carriage to cross the same point? (All carriages are the same width)
2 Answers
Explanation:
Let the length of each carriage be
Suppose that train accelerates at a constant rate of acceleration
We use the kinematic equation
where
Inserting various values for the first carriage we get
From (1)
Time taken to pass
Similarly time taken to pass
Therefore time taken by tenth carriage to pass through the reference point
Explanation:
α=
u is the speed gained in 4 secs
L=
L is the length of a carriage
t=
Δt