20. A train 700 m long is running at 72 kmph. if
it crosses a tunnel in 7 minute, length of the
tunnel is:
Answers
Answer:
500
Step-by-step explanation:
Length of train = 700 m
Length of tunnel = X (let)
Time taken to cross the tunnel = 1 minute = 60 sec.
Speed = 72 kmph = (72*5)/18 = 20 m sec.
To cross the tunnel train needs to travel = Length of train + length of tunnel = 700 +X
Now,
S*T = D
20 *60 = 700 +X
X = 1200 - 700 = 500
Length of tunnel = 500 m.
Answer:
Let the length of the travelled by the train be x
Speed of the train = 72 kmph = 72 × 5 = 20 m/s
18
Train crosses the tunnel in 7 min
= 7 × 60 = 420 sec.
W.K.T
Speed = Distance
Time
20 = x
420
x = 20 × 420
x = 8400 m
We need to subtract the length of the train.
So length of the tunnel = Distance travelled by the train - length of the train
= 8400 - 700 Length of the tunnel = 7700 m