Question

a train moving with a velocity of 12km/have find the time it takes to cross the bridge 1km long the length of train is 100m​

Answer 1

Answer:

Velocity= 12 km/h

Length of bridge= 1 km

Length of train= 100 m or 0.1 km

1 km= 1000 m

1m = 1/1000 km

100 m= 100/1000 km

= 0.1 km

Total length to be crossed = length of train+length of bridge

= 0.1 km + 1 km= 1.1 km(distance)

Speed or velocity= distance/time

time= distance/velocity or speed

= 1.1 km/12 km/h

= 11 km × h/ 10×12×km

= 11 h/120

= 0.0916666667 h

= 0.09 h(answer)

Thus, the time is 0.09 h.

Answer 2

Total distance required for the train to cross the bridge is,

d = (100 + 1000) m = 1100 m

The speed of the train is,

v = 12 km/h = 12 × 5 / 18 = (10/3) m/s

Hence the time taken to cross the bridge is,

t = 1100 / (10/3) = 330 s = 5.5 minutes.