In compressed state, a spring 3.00 meters long hanging from the ceiling has a potential energy of 2.0 joules. If the entire potential energy is used to release a ball of mass 1.2 kilograms vertically downward, then what is the kinetic energy of the ball when it reaches the ground?
A.
1.2 joules
B.
4.9 joules
C.
2.0 joules
D.
6.8 joules