Question

QIL. A train, 200 m long. is running at a speed of 42 km/hr. How
long will it take to cross a 80 m long tunnel?​

Answer 1

Answer:

24 SECONDS

Step-by-step explanation:

Total distance(to cross the tunnel completely) = 200+80=280m

speed=42km/hr

convert it into m/sec 42*5/18 (multiply by 5/18 to convert km/hr into m/sec)

speed=35/3 m/sec

now time taken to cross the tunnel = total distance/speed

total distance= 280m

speed= 35/3 m/sec

time=280/35/3

time = 24 seconds (by solving the above equation)

Answer 2

Answer:

Relative speed= 32+40=72 km/hrs =72*5/18 =20m/s. to cross each other they need to covered their length. So, Time taken to cover (132+10) m, with speed 20 m/s.=240/20=12sec

Step-by-step explanation:

I hope this is right answer.