1. The problem statement, all variables and given/known data Two solid spheres one of mass 'm' and other of mass '2m' are comin towards each other(translationally) with a velocity v1 and v2.After collision the sphere of mass 2m comes to rest and the sphere of mass m does oblique projectile motion at an angle 30 with the vertical till it reaches at a height "H"m wall.(no rotational till now). After reaching height H,it again goes for a horizontal projectile motion with initial velocity same as the final velocity of horizontal projectile motion.The time for horizontal projectile is 1/20sec.After reaching ground with a velocity v3(final velocity of horizontal projectile),it first acquires some w(omega) angular velocity and does pure rolling for some time. (Coefficient of friction is 1/squareroot(2) viz 1/1.414 on the left side if the wall).Find the time taken for pure rolling after reaching the ground on the left side of the wall??? 2. Relevant equations for pure rolling :wr = v momentum : pi = pf friction: f = N μ 3. The attempt at a solution ok i am stuck at right the first part it's either i am making a very dumb mistake or i am not seeing something taking +x to be right momentum initailly is 5m - 4m = 1m then final momentum in x must also be + 1m then since the 2m ball stops then the 1m ball must have a momentum of 1m ie it must be moving to the right and not to left as shown then how is it possible ? help thanks!