Discuss Forum
1. A train 125 m long passes a man, running at 5 km/hr in the same direction in which the train is going, in 10 seconds. The speed of the train is;
- A. 45 km/hr
- B. 45 km/hr
- C. 45 km/hr
- D. 45 km/hr
Answer: Option B
Explanation:
Given:
Length of train = 125 m
Time taken = 10 secs
Speed of man = 5 km/hr
Concept Used:
When 2 objects are moving in same direction, then
Relative speed = Difference between their speeds
Formula Used:
Speed = Distance/Time
1 Km/hr = (5/18)/s
Calculations:
Let the speed of train be v km/hr.
Speed of the man = 5 km/hr
Now, (v-5) × (5/18) = (125/10)
বা, (v-5) = (125/10) × (18/5) = 45 km/hr
বা, v = (45+5)= 50 km/hr.
Post your comments here: