a A gas is contained in a cylinder with a movable piston A 1

a. A gas is contained in a cylinder with a movable piston. A 12 lb weight is placed on top of the piston. Calculate the force exerted on the piston. (2 pts) 4. m 12 lb 5.4 F. 5.y#x1.81 : 53.312 N b. Calculate the pressure exerted on the gas in the cylinder if the diameter of the piston is 85 mm. (2 pts)

Solution

4)

a) mass = 12 lb

              = 5.443 kg

Force = m g

          = 5.443 x 9.81

force = 53.4 N

b)

pressure = force / area

diameter = 85 mm = 0.085 m

radius = 0.085 / 2 = 0.0425 m

area = pi x r^2

       = 3.14 x (0.0425)^2

       = 5.67 x 10^-3 m^2

pressure = 53.4 / 5.67 x 10^-3

pressure = 9415.3 Pa