Question

A hand-driven tire pump has a 2.50 cm diameter piston and a maximum stroke of 31.0 cm.

(a) How much work (J) do you do in one stroke if the average gauge pressure is 2.40 multiplied by 105 N/m2 (about 35 psi)? (You may consider this an isothermal process.)
(b) What average force(N) do you exert on the piston, neglecting friction and gravity?
Please give me the steps. Thanks

Answer 1

We calculate as follows:

d = 0.025 m
Δx = 0.31 m

W = pΔV = p(πd²)(Δx/4)
W = 2.4x10⁵(3.14x0.025²)(0.31/4) =36.5 J

F = W / Δx = 36.5 / 0.31 = 117.8 N

Hope this answers the question. Have a nice day.