1. The problem statement, all variables and given/known data Two particles move near the surface of the earth with u. acc 10 m/s^2 towards the ground . At the initial moment , the particles were located at one point in space and moved with velocities 3m/s and 4 m/s in opposite directions . Find the distance between the particles when their velocity vectors are mutually perpendicular . 2. Relevant equations s = ut + 1/2 at^2 3. The attempt at a solution the trajectory of the particles should form a half - ellipse . That's as far as i got , how should i relate the mutually perpendicular thing ??