Two particles A and B start moving with velocities 20m/s and 30√2m/s along x-axis and at an angle of 45 - Physics - Motion In A Plane

Question

Two particles A and B start moving with velocities 20m/s and
30√2m/s along x-axis and at an angle of 45 degree with x-axis
respectively in xy - plane from origin what is the relative
velocity of B w r t A ?

Satyendra Singh · Accepted Answer

Component of B in x-direction = vB cos 45vBx = 302 × cos 45vBx = 30 m/sComponent of B in v direction = vB sin 45vBy = 302 × sin 45vBy = 30 m/svAx = 20m/svAy = 0vABx = vBx - vAxvABx = 30-20vABx = 10 m/svABy = 30-0vABy = 30 m/sVAB = vABx2+vABy 2+2×vABx×vABy×cos αα = 90∘VAB = vABx2+vABy 2+0VAB = 102+302VAB=31
623 m/s

Two particles A and B start moving with velocities 20m/s and 30√2m/s along x-axis and at an angle of 45 degree with x-axis respectively in xy - plane from origin. what is the relative velocity of B w.r.t A ?