일반물리학 1 — Center of Mass and Linear Momentum: Problem 75

75 In Fig. 9-63, a bob of mass 10m is suspended from an inextensible string with negligible mass. When the bob is in equilibrium (at rest), two particles each of mass m strike it simultaneously with the speeds indicated. The particles stick to the bob. Find (a) the magnitude of the net impulse on the string due to the collision, (b) the velocity of the system just after the collision, and (c) the mechanical energy lost in the collision.