Two smooth balls, A of mass 2 kg and B of mass 3 kg, lie on a frictionless horizontal table. Ball A approaches with velocity (4 i + 3 j) m s⁻¹ while ball B is at rest. The line of impact is along the x-axis. If the coefficient of restitution between the balls is 0.5, what is the x-component of the velocity of ball A immediately after the collision?
a) −0.4ms−1
b) 0.4ms−1
c) 2.8ms−1
d) −0.8ms−1