Question 46

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Found in: Page 512

### Physics for Scientists and Engineers: A Strategic Approach with Modern Physics

Book edition 4th
Author(s) Randall D. Knight
Pages 1240 pages
ISBN 9780133942651

# A cylinder contains of oxygen (O2) at a pressure less than . The cap on one end of the cylinder is held in place only by the pressure of the air. One day when the atmospheric pressure is , it takes a force to pull the cap off. What is the temperature of the gas?

The temperature of the gas is

See the step by step solution

## Step 1 : Defining Ideal Gas law

Given : A -diameter, -long cylinder contains of oxygen at a pressure less than . When atmospheric pressure is , it takes a force to pull the cap off.

The ideal gas law () relates the macroscopic properties of ideal gases.

Since the pressure comes from inside the gas, we can apply the ideal gas law to find an expression for the temperature
Knowing that we are giving the mass and not the number of moles, we can rewrite the previous formula as follows., where is the molar mass of the gas inside and is the mass of that gas.

## Step 2 : Finding the temperature of the gas

Based on Newton's first law and the definition of pressure, we can write for the cap that
Where is the internal pressure, is the atmospheric pressure,

is the area of the cap and is the force we have to apply to move the cap.We can now substitute the expression we found for pressure into our result for temperature:

Remembering that for a cylinder , we can further simplify to If we apply our numerical input data, we find the value for the temperature inside as follows.

Inserting the values, we get