A piston in a gas supply pump has an area of $500\text{ cm}^2$ and, in one stroke, it travels $30\text{ cm}$. The pump pushes the gas against a constant pressure of $4000\text{ Pa}$. How much work is done by the piston in one stroke?
- A$60\text{ J}$
- B$6.0 \times 10^3\text{ J}$
- C$6.0 \times 10^5\text{ J}$
- D$6.0 \times 10^7\text{ J}$