# Year 8 Physics

• ## Pressure Applications

• ### Classwork

• We corrected the HW and went through the last question (which was optional).
• We made notes on some examples of things that are designed to exert high pressures and low pressures.
• ### Homework

• Answer Q5-6 on P115 and hand in on Tuesday morning before reg.
• ## Pressure

• ### Classwork

• We went through the test on sound.
• We did some example calculations using the formula P = F/A.
• We calculated the pressure we exert on the floor - we will go though this next lesson.
• ### Homework

• Answer Q1-4 of this sheet. Q5 is optional.
• Hand in on Monday.
• ## Test

• ### Classwork

• We did some recap work, then did the test.
• ### Homework

• No homework.
• ## Loudness and hearing damage

• ### Classwork

• We came up with some questions from the topic so far.
• I gave you some feedback on your graphs, and we used a log scale to plot animal hearing ranges.
• We made some notes on loudness of sound and hearing damage.
• Notes from the lesson are here.
• ### Homework

• Revise for a test next week on this stuff.
• If you missed the oscilloscope lesson then watch the demo here and have a look at this page and P50 of the textbook.
• ## Loudness and graphs

• ### Classwork

• We went through the HW and corrected a few common mistakes.
• We did a survey of sound levels around the school - I will post the results on here soon.
• Most places were around 60-70dB. The only results outside this range were the library at 40dB and the cafe at 76dB.
• We started to represent some data about animal hearing ranges graphically.
• ### Homework

• Finish your graph of animal hearing ranges.
• Hand in on Monday morning before registration.
• ## Sound and frequency

• ### Classwork

• I gave you some feedback on the HW.
• We made some notes on sound and frequency.
• We investigated the frequency of different notes in a musical scale.
• ### Homework

• Watch this video about echolocation.
• Answer Q1,3,4 on P55. Hand in on Monday before morning registration.
• ## Introducing Sound

• ### Classwork

• Oops - we were meant to be doing sound, not pressure for this topic. So we started sound.
• We got an idea about what you already know about sound, and defined some basic terms.
• We went outside to try to measure the speed of sound. Here is the video of the attempt I used to collect data and here is the results table and graph.
• Depending on how you draw the line of best fit, the speed works out to be about 300m/s which is not terrible - the speed of sound in air is really 330m/s.
• The gaps in the graph were for people who I could't see when they lifted the paper accurately so I left them out.
• ### Homework

• Asnwer Q1-3 on P52 and hand in on Monday morning before registration.
• You may need to read some of the preceding pages in the textbook.
• ## Introducing Pressure

• ### Classwork

• We went through the test on light from last term.
• We recapped on forces, and started to make some notes about pressure.
• ### Homework

• Watch this video about pressure.
• Bring any questions you have to next lesson.
• ## Dispersion and Total Internal Reflection

• ### Classwork

• We did this difficult question about refraction of light.
• We investigated what can happen when a ray of light passes through a triangular prism.
• We made notes on dispersion and total internal reflection.
• ### Homework

• Revise for a short test on light next week - what you need to know is here.
• ## Refraction

• ### Classwork

• We investigated the refraction of light through a perspex block.
• ### Homework

• Watch this video up to 8:38. This recaps on everything we have done so far, so there is no need to take extra notes, but you are welcome to add to your notes if you like. It also introduces dispersion which will will soon learn more about.
• Also, please learn the colours of the spectrum in order before next lesson - there will be a quiz.
• ## Reflection

• ### Classwork

• We investigated the reflection of light from a mirror and found that the angle of incidence equals the angle of reflection.
• ### Homework

• Homework is on Yammer - your task is to create a video demonstrating refraction.
• ## Light

• ### Classwork

• We made some notes on the speed light travels and about light travelling in straight lines.
• We built and tested a pinhole camera, and tried modifying it in different ways.
• We did not make as much progress as we might have done under ideal circumstances - please reflect on this for next lesson.
• ### Homework

• Hand in Monday morning before registration.
• ## Test Feedback

• ### Classwork

• We went through the test.
• We did an experiment to find out which materials can affect a magnetic field.
• We introduced the next topic - light.
• ### Homework

• Use your phone or a digital camera to take a picture or a video of something interesting happening with light.
• Post it to the Year 8 Physics Mr Gravell group which I have created on Yammer.
• Do this before next lesson.
• The group is closed and I have added you to it, except A.M. A.S. and O.S. because I could not find you on Yammer. If you three can join Yammer over the weekend I will try to add you to the group next week.
• ## Test

• ### Classwork

• We did the test.
• ### Homework

• No homework.
• ## Relay and Electric Bell

• ### Classwork

• We looked in detail at a relay and an electric bell, and answered questions about how an electric bell works.
• We went over a few areas of difficulty before next week's test.
• ### Homework

• Revise for an end of topic test on magnets next week.
• ## Uses of Electromagnets

• ### Classwork

• We went through the homework, and then built and tested loudspeakers.
• We discussed how loudspeakers work, and considered ways to make them louder.
• ### Homework

• Watch this video which demonstrates a relay switch in action.
• Watch this video which explains how relay switches work in a bit more detail.
• We will demonstrate a relay switch next lesson, and also look at the electric bell and how it works.