A train with a length of 360 metres is travelling at a speed of 45 kilometres per hour. How long will it take to cross a 140-meter bridge?
A. 40 sec
B. 42 sec
C. 45 sec
D. 48 sec
Answer:A
A train with a length of 360 metres is travelling at a speed of 45 kilometres per hour. How long will it take to cross a 140-meter bridge?
A. 40 sec B. 42 sec C. 45 sec D. 48 sec
Explanation: To convert km/hr to m/s, use the formula X km/hr = X x 5/18 m/s.As a result, Speed = 45 x 5/18 m/sec = 25/2 m/sec.(360 + 140) m = 500 m is the total distance to be travelled.Time = Distance / Speed Required time = 500 x 2/25 sec = 40 sec