Question

A 800 train meters long is travelling at a speed of 78 km/hr. If it crosses a tunnel in1 menute than what is the length of the tunnel.

Answer 1

Hello!

Let length of tunnel is x meter

✓ Distance = (x + 800) m
✓ Time = 1 min = 60 Seconds

Then,

Speed = 78 km/hr = 78 × 5 / 18 ms⁻¹ = 65 /3 ms⁻¹

Since,

Distance = Speed × Time

⇒ x + 800 = 65 / 3 × 60

⇒x + 800 = 20 × 65 = 1300

⇒ x = 1300 − 800 = 500

Hence,
The length of the tunnel is 500 m.

Cheers!