What force would have to be applied to the hand pump to reach the final pressure? — States of Matter and Gaseous State Chemistry Question

💡 Solution & Explanation

The maximum force is required at the end of the stroke when the pressure inside the pump reaches the tire pressure of 8 bar. Since the external atmospheric pressure is 1 bar, the gauge pressure the piston must overcome is ΔP = 8 - 1 = 7 bar = 7 × 10^5 N/m^2. Area of piston A = 4 cm^2 = 4 × 10^-4 m^2. Force F = ΔP × A = 7 × 10^5 × 4 × 10^-4 = 280 N. The closest option is (b) 320 N.