A train moving at 72 km/h passes a platform 300 m long. How long does it take to
Practice Questions
Q1
A train moving at 72 km/h passes a platform 300 m long. How long does it take to cross the platform completely?
10 seconds
15 seconds
20 seconds
25 seconds
Questions & Step-by-Step Solutions
A train moving at 72 km/h passes a platform 300 m long. How long does it take to cross the platform completely?
Step 1: Convert the speed of the train from km/h to m/s. To do this, divide the speed by 3.6. So, 72 km/h ÷ 3.6 = 20 m/s.
Step 2: Identify the total distance the train needs to cover to completely cross the platform. This distance is the length of the train plus the length of the platform. We assume the length of the train is 300 m, so total distance = 300 m (train) + 300 m (platform) = 600 m.
Step 3: Use the formula for time, which is time = distance ÷ speed. Here, distance = 600 m and speed = 20 m/s.
Step 4: Calculate the time taken to cross the platform. So, time = 600 m ÷ 20 m/s = 30 seconds.
Relative Speed and Distance – Understanding how to calculate the time taken to cross an object based on speed and total distance.
Unit Conversion – Converting speed from km/h to m/s to ensure consistent units in calculations.
