A pulley with a radius of $0.40\,\text{m}$ holds weights of $20\,\text{N}$ and $15\,\text{N}$ using a thin string, as illustrated. The weights are lifted by turning the pulley slowly clockwise through an angle of $60^{\circ}$. What is the rise in the total gravitational potential energy of the weights?
- A$0.33\,\text{J}$
- B$2.0\,\text{J}$
- C$2.1\,\text{J}$
- D$15\,\text{J}$