A 10-Kg Ball Is Attached to the End of a 2

Multiple Choice

A 1.0-kg ball is attached to the end of a 2.5-m string to form a pendulum. This pendulum is released from rest with the string horizontal. At the lowest point in its swing when it is moving horizontally, the ball collides elastically with a 2.0-kg block initially at rest on a horizontal frictionless surface. What is the speed of the block just after the collision?

A) 2.3 m/s
B) 4.7 m/s
C) 3.5 m/s
D) 3.0 m/s
E) 7.0 m/s