Question
a body is projected at 40m/s from the horizontal ground at an angle 60 degree with the vertical. time at which it is moving perpendicular to its direction of motion is
Joshi sir comment
when particle will move perpendicular to its initial direction its velocity in its ititial direction will become 0. and component of gravity in that direction = gsin30
30 degree will be the angle of motion of particle from horizontal.
now use v = u + at, 