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Examoogle • User • info@examoogle.com • EE-2024-8821
Chapter 1 of 12 • Page 1 of 248🔒 Protected PDF • Watermarked
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दोन गाड्या A आणि B विरुद्ध दिशेने अनुक्रमे 66 किमी/तास आणि 60 किमी/तास वेगाने धावत आहेत. जर गाडी A ची लांबी 240 मीटर असेल आणि त्या एकमेकींना 10 सेकंदात ओलांडत असतील, तर गाडी B ची लांबी शोधा.
110 मी
120 मी
150 मी
144 मी
110 मी
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).