A force of 30N acts on the piston of a hand pump with an area of 4 cm2. With what force does the air press against

A force of 30N acts on the piston of a hand pump with an area of 4 cm2. With what force does the air press against the inner surface of a bicycle tube with an area of 20 dm2?

Because the pressure created on the piston of the hand pump is equal to the pressure on the inner surface of the bicycle tube, then we express the force of air pressure from the equality: F1 / S1 = P = F2 / S2, whence F2 = F1 * S2 / S1, where F1 (the force acting on piston) = 30 N; S1 (pump piston area) = 4 cm2 (in SI S1 = 4 * 10-4 m2); S2 (area of the inner surface of the chamber) = 20 dm2 (in SI S2 = 0.2 m2).

Calculation: F2 = F1 * S2 / S1 = 30 * 0.2 / (4 * 10-4) = 15 * 103 N (15 kN).

Answer: Air presses with a force of 15 kN.