If two objects move in same direction at different speeds
If speed of 1st object = x km/hr and
Speed of 2nd object = y km/hr
Therefore, their relative speed = (x – y) km/hr [x > y], then
Time after which the two objects meet = distance / relative speed = d km/ (x – y) km/hr
We know, speed of one object with respect to another is called relative speed.
If time after which they meet is given, i.e., time = t hrs.
Then, distance covered in ‘t’ hours = time × relative speed = t hours × (x – y) km/hrNow we will learn to calculate when two object move in same direction at different speeds.
Two athletes are running from the same place at the speed of 6 km/hr and 4 km/hr. find the distance between them after 10 minutes if they move in the same direction.
When they move in same direction,
Their relative speed = (6 – 4) km/hr = 2 km/hr
Time taken = 10 minutes
Distance covered = speed × time
= (2 × 10/60) km
= 1/3 km
= 1/3 × 1000 m
= 333.3 m