## Physics for Scientists and Engineers: A Strategic Approach with Modern Physics (3rd Edition)

(a) The force exerted on the flat end of each cylinder is $2.9\times 10^4~N$ (b) 30 football players would need to hang from the lower cylinder to pull the two cylinders apart.
(a) The pressure difference between the inside of the cylinders and the outside of the cylinders is $1~atm$. We can find the force exerted on the flat end of each cylinder. $F = \Delta P~A$ $F = \Delta P~\pi~r^2$ $F = (1.013\times 10^5~N/m^2)(\pi)(0.30~m)^2$ $F = 2.9\times 10^4~N$ The force exerted on the flat end of each cylinder is $2.9\times 10^4~N$ (b) We find the weight of one football player. $weight = (100~kg)(9.80~m/s^2) = 980~N$ We then find the number $n$ of football players. $n\times ~weight = 2.9\times 10^4~N$ $n = \frac{2.9\times 10^4~N}{weight}$ $n = \frac{2.9\times 10^4~N}{980~N}$ $n = 30~players$ 30 football players would need to hang from the lower cylinder to pull the two cylinders apart.