A uniform solid block has weight $500\,\text{N}$, width $0.4\,\text{m}$ and height $0.6\,\text{m}$. It is positioned on the edge of a step with depth $0.8\,\text{m}$, as illustrated. The block is pushed over the step edge and turns through $90^{\circ}$ before settling so that the $0.6\,\text{m}$ edge is horizontal. What is the change in gravitational potential energy of the block?
- A$300\,\text{J}$
- B$400\,\text{J}$
- C$450\,\text{J}$
- D$550\,\text{J}$