Three steel spheres move along the same straight line. Sphere 1 has mass 0.50kg and velocity 4.0ms−1 east. Sphere 2 has mass 1.0kg and is initially at rest. Sphere 3 has mass 2.0kg and velocity 1.0ms−1 west. Determine the velocity (magnitude and direction) of the center of mass of the three-sphere system at this instant.