Steam at 120 C and at atmospheric pressure of 101.3 kPa is added to a hollow cyl
ID: 1498967 • Letter: S
Question
Steam at 120 C and at atmospheric pressure of 101.3 kPa is added to a hollow cylindrical steel can that is then sealed and allowed to cool. The can is 0.20 m tall and 0.10 m in diameter, and the can stands on the flat part of its surface.
Part A
What is the pressure inside the can at 101 C?
Part B
What is the magnitude of the total force exerted by the atmosphere on the whole curved portion of the can exterior?
Part C
What is the magnitude of the force exerted by the atmosphere on the top flat portion of the can exterior?
Explanation / Answer
Here
T1 = 120 degree C = 393 K
T2 = 101 degree C = 374 K
a)
P1 = 101.3 kPa
Using ideal gas equation
P1/T1 = P2/T2
101.3/393 = P2/374
P2 = 96.40 kPa
the pressure inside the can is 96.40 kPa
b)
magnitude of total force extered by exerted on the curved portion = projected area * pressure
magnitude of total force extered by exerted on the curved portion = 0.20 * 0.10 * 1.01 *10^5 Pa
magnitude of total force extered by exerted on the curved portion = 2020 N
c)
magnitude of force exerted by atmosphere on the top flat portion = pi * (r)^2 * pressure
magnitude of force exerted by atmosphere on the top flat portion = pi * (0.10/2)^2 * 1.01 *10^5 N
magnitude of force exerted by atmosphere on the top flat portion = 793.1 N