Revision as of 05:16, 17 April 2009

Outcomes

Pupils apply the principle of moments for a balanced object.
Pupils investigate how the upward forces on a light beam varies with the position of a heavy object placed on the beam.

1.25 recall and use the principle of moments for a simple system of parallel forces acting in one plane
1.26 understand that the upward forces on a light beam, supported at its ends, vary with the position of a heavy object placed on the beam

Pupils apply the principle of moments for a set of 3 example questions given here, one example will test the idea that the mass acts from the centre of gravity Principle of moment example quesitons

Bridge Investigation - Pupils investigate how the upward force on a light beam (bridge) varies with the position of a heavy object (truck) placed on the beam. The set up has a forcemeter on one end and a sting hold the other end. The pupils should produce a graph on how the force varies with the distance to the end.

Group the class into 5 groups of increasing ability. There are three Moment problems of varing difficulty. 1) 2) To find the mass of a retort stand using the principle of moments and 3) to find the centre of mass of a student.
Have two groups attempt activity 1, another two groups of higher ability attempt activity 2 and one group of highest ability can be challenged by activity 3. All three activities have cards explaining what they need to do and also have a Moments hint card to help groups who are stuggling.
They should be asked to read through the card and have a look at the equipment. They should then discuss the activity as a group and then go onto try solving it.
If there is time they can present their problem and how they solved it.

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

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 ==Main Body of Lesson==
-* Pupils apply the principle of moments for a set of 3 example questions given here, one example will test the idea that the mass acts from the centre of gravity [[Principle of moment example quesitons]]
 * [[Bridge Investigation]] - Pupils investigate how the upward force on a light beam (bridge) varies with the position of a heavy object (truck) placed on the beam.  The set up has a forcemeter on one end and a sting hold the other end. The pupils should produce a graph on how the force varies with the distance to the end.