Revision as of 03:44, 21 September 2009

Outcomes

5.4 recall and use the relationship between pressure, force and area : Pressure = force / area

The students will use measuring cylinders stuffed with foam to discover the relationahip between force and pressure and area and pressure.
SET 1 - Measuring cylinders will have the same cross sectional area of foam but have different length metal cylinders (to change the force) to drop into the cylinder. They watch or even record the distance the foam is pushed down.
SET 2 - Measuring cylinders will be of different CSA's and have equal mass metal cylinders with different CSA's. They watch or record how the foam is depressed by object of varying CSA.

Pool the students thoughts on how the force affects pressure and how CSA affects pressure. Try to encourage a quantitative relationship.
From these observations/discoveries help the pupils derive the formula for pressure.
Split the class into groups and hand each group a
PRESSURE YOU EXERT ON THE GROUND - Have the pupils draw round their shoes on a piece of graph paper and count squares to determine the area of their shoe prints. Using the Scales they can find their mass - use W = mg to find their Weight and calcualte the pressure.

Set up a balloon which is electrostatically charged, on the ceiling, attach a string with a

Electrical Force - balloons for electrostatics, rice in a plastic bottle charging polythene rods and using watch glass show repulsion

A tank with water in it will be heavy and so is only to be moved by the technician; please refer to the Manual handling section of the Laboratory Lessons Health and Safety Risk Assessment
When using springs goggles must be worn
The main risk is from the vacuum pump and apparatus. The specific risk assessment must be read before using the apparatus.
General Laboratory Health and Safety Risk Assessment

@@ Line 13: / Line 13: @@
 * Pool the students thoughts on how the force affects pressure and how CSA affects pressure.  Try to encourage a quantitative relationship.
 * From these observations/discoveries help the pupils derive the formula for pressure.
+* Split the class into groups and hand each group a
 * PRESSURE YOU EXERT ON THE GROUND - Have the pupils draw round their shoes on a piece of graph paper and count squares to determine the area of their shoe prints.  Using the Scales they can find their mass - use W = mg to find their Weight and calcualte the pressure.