FIGURE 8-7 Two Masses M₁ = 2

FIGURE 8-7 Two masses M₁ = 2.0 kg and M₂ = 4.0 kg are attached by a string as shown in Figure 8-7. M₁ falls vertically down and M₂ moves on a frictionless surface. Initially the system is at rest. Use g = 10 m/s².
-Refer to Figure 8-7. What is the potential energy of the mass M₁ just before it touches the ground?

A) 2.3 J
B) 2.5 J
C) 0 J
D) 4 J
E) 5.2 J