In a robotic subsea exploration probe, a hydraulic actuator is used to operate a sample-collection gripper. The actuator applies a force of 315 N315\text{ N}315 N normal to the circular face of a small piston. The pressure transmitted through the hydraulic fluid is 7.5×105 Pa7.5 \times 10^5\text{ Pa}7.5×105 Pa.
Calculate the cross-sectional area of the piston face. Give your answer in standard form and include the correct SI unit.