Question

A body is simultaneously given two velocities, one 10 m s due east and other 20 ms¹ due north-west. Calculate the resultant velocity.​

Answer 1

Given: First velocity (v1) = 10 m/s due east

= (10 i + 0 j) m/s

Second velocity (v2) = 20 m/s due north-west = [ 20 cos (90° + 30°) i + 20 sin (90° + 30°) j ] m/s

= [ - 20 sin (30°) i 20 cos (30°) j m/s

= (- 10 i + 17.32 j) m/s

Now, we shall find the resultant of these two velocities by their vector additions.

V resultant = (vi) + (vz)

= (10 i + 0 j) m/s + (- 10 i + 17.32 j) m/s

= 17.32 j m/s

= 17.32 m/s due north

Hence, the resultant velocity will be 17.32 m/s due north.