Join 60,000+ competitive exam aspirants
or with email
Your Cart
Subtotal₹0
Total₹0
Examoogle • User • info@examoogle.com • EE-2024-8821
Chapter 1 of 12 • Page 1 of 248🔒 Protected PDF • Watermarked
Join 60,000+ competitive exam aspirants
ಎರಡು ರೈಲುಗಳು A ಮತ್ತು B ಕ್ರಮವಾಗಿ 66 km/hr ಮತ್ತು 60 km/hr ವೇಗದಲ್ಲಿ ವಿರುದ್ಧ ದಿಕ್ಕಿನಲ್ಲಿ ಚಲಿಸುತ್ತಿವೆ. ರೈಲು A ನ ಉದ್ದ 240 m ಆಗಿದ್ದು, ಅವು ಪರಸ್ಪರ 10 ಸೆಕೆಂಡುಗಳಲ್ಲಿ ಹಾದುಹೋದರೆ, ರೈಲು B ನ ಉದ್ದವನ್ನು ಕಂಡುಹಿಡಿಯಿರಿ.
110 m
120 m
150 m
144 m
110 m
Convert relative speed to m/s by multiplying with 5/18. Total distance = Relative speed × time. Then subtract length of train A from total distance.
Speed of train A = 66 km/hr, Speed of train B = 60 km/hr, Length of train A = 240 m, Crossing time = 10 s
Speed=TimeDistance,Relative Speed=S1+S2(opposite directions)
Convert relative speed to m/s by multiplying with 5/18. Total distance = Relative speed × time. Then subtract length of train A from total distance.
Forgetting to convert km/hr to m/s before multiplying by time in seconds, or failing to add speeds for opposite directions.
Calculate Relative Speed
Since the trains are running in opposite directions, their speeds are added.
Relative Speed=66+60=126 km/hr
Convert Speed to m/s
To match the units of length (m) and time (s), convert 126 km/hr to m/s.
126×185=7×5=35 m/s
Calculate Total Distance
Total distance is the sum of lengths of both trains.
Distance=Speed×Time=35×10=350 m
Find Length of Train B
Subtract the length of train A from total distance to find the length of train B.
LB=350−240=110 m
A is correct because the calculated length of train B is 110 m.
This concept is vital for Boat and Stream problems where effective speed changes based on direction (upstream/downstream).