Join 60,000+ competitive exam aspirants
or with email
Your Cart
SubtotalтВ╣0
TotalтВ╣0
Examoogle тАв User тАв info@examoogle.com тАв EE-2024-8821
Chapter 1 of 12 тАв Page 1 of 248ЁЯФТ Protected PDF тАв Watermarked
Join 60,000+ competitive exam aspirants
A train 150m long is running at 54 km/hr. How long will it take to cross a platform 250m long?
20┬аsec
26.67┬аsec
30┬аsec
40┬аsec
26.67┬аsec
Use the conversion factor 5/18 for km/hr to m/s: 54imes(5/18)=15 m/s. Total distance is 150+250=400m, so time =400/15=80/3тЙИ26.67 sec.
Length of the train L1 = 150m, length of the platform L2 = 250m, and speed of the train v = 54 km/hr.
t=vL1тАЛ+L2тАЛтАЛ
Use the conversion factor 5/18 for km/hr to m/s: 54imes(5/18)=15 m/s. Total distance is 150+250=400m, so time =400/15=80/3тЙИ26.67 sec.
Students often forget to add the platform length to the train length or fail to convert km/hr to m/s before calculation.
Calculate total distance to be covered
To cross the platform completely, the train must cover its own length plus the length of the platform.
D=150m+250m=400m
Convert speed to m/s
The speed is given in km/hr, so we convert it to m/s by multiplying with 5/18.
v=54imes185тАЛ=15┬аm/s
Calculate time taken
Using the time formula t=D/v, we divide the total distance by the speed in m/s.
t=15400тАЛ=26.67┬аsec
B is correct because the total distance of 400m divided by the speed of 15m/s results in 26.67 seconds.
This concept is a precursor to 'Trains' problems involving two moving bodies where you must calculate relative speed (sum of speeds for opposite directions, difference for same directions).
Get instant step-by-step AI explanations, full shift Previous Year Papers (SSC GD, RRB, SSC JE), and regional rank analysis on the official Examoogle App.
Free Download тАв 100K+ Aspirants