A weightlifter raises some masses to a vertical height of $1.8\,\text{m}$. The gravitational field strength $g$ is $10\,\text{N kg}^{-1}$. As the lift takes place, the gravitational potential energy of the masses rises by $4500\,\text{J}$. What is the total mass lifted?
- A$25\,\text{kg}$
- B$250\,\text{kg}$
- C$450\,\text{kg}$
- D$810\,\text{kg}$