70.
Two trains whose respectively lengths are 200
metres and 250 metres crossed each other in 18
seconds. while travelling in opposite direction,
whereas they crossed each other in 1 minute while
travelling in the same direction. Find the speed of
the faster train.
(A) 52.5
(B) 58.5
(C) 62.5
(D) 66.5
Answers
Answer:
lengths of train = 240 m and 360 m; crossed each other in 30 seconds in opposite directions; 1 minute 40 seconds i.e. 100 seconds in same direction. That is,
speed = distance / time; lengths or distance = speed x time.
distance or lengths = 600 meters same directions and 120 meters opposite ; and
time = 100 seconds same direction and 30 seconds opposite.
total length = 240+360 = 600 meters,
speed of faster train x and slower’s y (in m/s). So,relative speed (while moving in opp. direction )= x + y and,relative speed (moving in same direction) = x - y). It crossed each other (moving in opposite direction) in 30 seconds, traveled = 600 m.
Relative speed = x + y = 600/30 = 20 m/s; crossed each other (moving in same direction) in 100 seconds 60 seconds + 40 seconds = 100 seconds.
Total distance traveled = 600 m.
Relative speed =x - y = 600/100 = 6 m/s;
Solving, x = 13 m/s.
x is the speed of the faster train; Speed in km / hour = 13 / 1000 x 3600 = 46.8 kilometers. per hour.
Hope it helps you
Answer:
(b) 58.5 km/hr.
Step-by-step explanation:
this is your answer
