Relative Motion in Two Dimension: Practice Problem & Solution
A man wishes to swim across a river 400 m wide flowing with a speed of 3m/s, such that he reaches the point just in front on the other bank in time not greater than 100 sec. The angle made by the direction he swims and river flow direction is :
Solution Explained:
To solve this problem, we apply the core principles of Relative Motion in Two Dimension. Understanding the underlying formula is key to arriving at the correct answer below:
Distance travelled in y-direction = 400 m
Time to cross = 100 sec
So, Speed in y-direction = 4 m/s
Speed in x-direction = 3m/s
So, angle = 90 +37 =127º
Why are we adding the two angles at the end?
Because we need to find angle with direction of flow of river.