a particle is moving with a velocity v..........gets turned by an angle 90 degrees..........its mass is m.........find the change in momentum...........PLS draw an FBD...............!!!!!!!!!!!!!!!!!!1PLS HELP TO CLEAR THIS CONCEPT>>>>>

let the particle travel along the positive x axis initially. Therefore its momentum is mv(i). If it turns by 90 degree it could travel along positive or negative y axis(which one exactly is inconsequential to te final result. lets just think positive and choose the positive y axis). Therefore its final momentum will be mv(j). change in momentum =  -mv(i)+mv(j)

                                                                                                                     =   mv(j-i)

therefor magnitude of change in momentum = mv*(2^0.5) and direction will along a line making anangle 45 degree with the initial velocity vector.