Wednesday, 31 August 2011

Projectile Motion using Angry Birds

Used Tracker motion analysis today to help us understand more about how projectile motion works. The video below shows how to use the autotracker function to analyse the motion of the Angry Bird.



We used the analysis to figure out how the horizontal and vertical motion of the bird changed over time. We also calculated the approximate length of Angry Bird required to give an acceleration similar to gravity. The question sheet below was used as a guide.

Projectile Motion Using Angry Birds


Tuesday, 30 August 2011

Projectiles

We started off with the simplest type of projectile - those that are projected horizontally. They therefore have an initial vertical velocity of zero so are pretty much the same as our calculations on bouncing balls and the like.



Things get a little more complicated when you launch projectiles into the air at an angle because the initial vertical velocity is no longer zero. If this is the case then you must think about the horizontal velocity and the vertical velocity separately.

Tuesday, 21 June 2011

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.

Friday, 10 June 2011

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.

Wednesday, 8 June 2011

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).

Tuesday, 7 June 2011

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

Monday, 6 June 2011

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)