Title: Gas Pressure
Objectives
Students understand the concept of pressure and how to calculate it
Students use particle model to examine gas pressure
Teacher notes and overview of daily lessons
This is a 55 min lesson plan. Students will be introduced concept of pressure and gas pressure in particular in this lesson.
Optional: There is a coke implosion demo as an option for students to think about air pressure (see website
Detailed Daily Plan
Warm-up/Entry Task:
Display an inflated ball and a deflated ball on the front desk. Ask for observations of the ball. How does it behave and why?
Activity 1:Cutting apple with a knife
- Can you cut the apple using the flat side of knife? Why or why not?
Introduction of Pressure (Pa) = Force (N)/ Area (m2),
Challenge:
For those students who are ready for numbers, use the following:
- What is the pressure an apple receives from the knife with 50 N force.
( flat side is 0.01 m2, the sharp side is 0.0001 m2)
- If a hammer applies a 10 N force to the nail head with 0.02 m2 surface, how much pressure does the nail receive (500)? The tip of the nail is only about 0.0001 m2, how much pressure does the nail give to the wood?(100,000)
Activity 2: Particle model of gas pressure
Question: Remember the food color diffusing in water or scentdiffusing in air? The particles are MOVING. What will happen when the particles hit the wall of the container? How will you show it?
Because particles are moving in liquid and in gas, they hit the walls of a container. The surface of the wall will receive the force from the particles. This is how they build up pressure.
Materials
- Inflated ball and deflated ball for demo
- Apple and knife for demo
Exit Slip Included
Pressure Exit Slip
NamePeriod
1. Does A or B have higher pressure and why?
2. What could you do to change the pressure in this system?
AB