5D - Vectors and vector diagrams

We draw vector diagrams to simulate what we see in the real world. I think some people still don't get this.

As I see it, there are two main rules when drawing vector diagrams:

1. Join your vectors 'tip to tail'
2. Use your common sense!

If the resulting velocity, displacement or force looks wrong then use your common sense. Th diagram is only showing you what will happen if you put these two velocities together or these two forces together.

5D - Errors and Uncertainties 2

When we have more than one uncertainty to deal with, we need to choose which one to take into account for our final answer. To do this, we use the value that has the greatest percentage uncertainty.

The percentage uncertainty is expressed as a percentage whereas the absolute uncertainty is written as a number.

5D - Errors and uncertainties

There are three types of uncertainty we need to consider for Higher Physics:

• Reading; occurs when taking a measurement visually
• Random; the subtle differences between experiments that produce differing results are caused by random errors
• and Systematic; when there is something wrong with the equipment or the way in which it is used.

We can limit the effect of random errors by carrying out repeated measurments. You need to know how to calculate the mean and the error in the mean (approximate random uncertainty).

4H - Radiation types

Learning outcome: 

•We are learning what radiation is and its different types.

Success criteria: 

•Be able to describe the effects that radiation can have 

•Be able to give examples of sources of radiation

•Be able to give at least one method of detecting radiation

•Be able to describe the different types of radiation and how to protect ourselves against them

4H - X-rays

Learning outcome:  We are learning how x-rays work and how they can be used to diagnose health problems

Success Criteria: 

•Be able to describe one use for x-rays in medicine

•Be able to describe how x-rays can be detected

•Be able to describe how x-rays behave when they enter the human body

•Be able to describe the advantages of computerised tomography (CAT scan)