Q. 48

Expert-verified
Found in: Page 568

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

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

# nitrogen molecules collide with a wall each second. Assume that the molecules all travel with a speed of and strike the wall head-on. What is the pressure on the wall?

The pressure on the wall is

See the step by step solution

## Step 1 : Given information and formula used

Given :

Number of nitrogen molecules collide each second :

Area of wall :

The molecules all travel with a speed of :

Theory used :

The nitrogen molecules collide with the wall and bounce back, changing their momentum in the process. The force exerted by the gas on the wall can be calculated by :

...(1)

## Step 2 : Calculating the pressure on the wall

The rate of collision is :

Nitrogen has a molecular mass of . However, because nitrogen is a diatomic gas, one molecule has a molecular mass of . When we convert this to kilograms, we obtain :

To get (), we plug the values for , and into equation (1) :

The pressure is the force per area, so we can get the pressure by :