1. vectors and scalars

2. weight and mass We have seen that weight is a force that results from the attraction of a mass towards another mass (eg the Earth). This force must have a direction (ie towards the centre of the Earth). We have seen that weight is a force that results from the attraction of a mass towards another mass (eg the Earth). This force must have a direction (ie towards the centre of the Earth).

3. weight and mass Any measurement that has a direction as well as a magnitude (ie size), is a vector measurement. Any measurement that has a direction as well as a magnitude (ie size), is a vector measurement. Can you think of any quantities that we measure that have a direction as well as a size? Can you think of any quantities that we measure that have a direction as well as a size?

4. weight and mass Any measurement that has no direction and only a magnitude (ie size), is a scalar measurement. Any measurement that has no direction and only a magnitude (ie size), is a scalar measurement. Can you think of any quantities that we measure that have a only a size, and no direction? Can you think of any quantities that we measure that have a only a size, and no direction?

5. scalars and vectors The table below gives some examples of scalar quantities and vector quantities. The table below gives some examples of scalar quantities and vector quantities. SCALARVECTOR Mass (kg) Weight (N) Distance (m) Displacement (m) Speed (ms -1 ) Velocity (ms -1 ) Energy (J) Time (s)

6. scalars and vectors If you combine two or more scalar quantities you just add them arithmetically. If you combine two or more scalar quantities you just add them arithmetically. eg 2kg plus 5kg equals 7kg, or eg 2kg plus 5kg equals 7kg, or starting with 100J and using 80J leaves 20J remaining. starting with 100J and using 80J leaves 20J remaining.

7. scalars and vectors Combining vector quantities is not as straight forward. Direction must be considered as well as size. Combining vector quantities is not as straight forward. Direction must be considered as well as size. eg Combining a force of 5N down with a force of 3N up will be different to combining forces of 5N up and 3N up. eg Combining a force of 5N down with a force of 3N up will be different to combining forces of 5N up and 3N up.

8. scalars and vectors Combining a force of 5N down with a force of 3N up will give a resultant force of 2N down but combining forces of 5N up and 3N up will give a resultant force of 8N up. Combining a force of 5N down with a force of 3N up will give a resultant force of 2N down but combining forces of 5N up and 3N up will give a resultant force of 8N up. Work through the sheet ‘Scalars Vectors’ Work through the sheet ‘Scalars Vectors’