AS Physics Wednesday 12th Sept.notebook
November 12, 2012
Raj Perera
raj.perera@oaklands.ac.uk
Practical measurement of density using a micrometer screw gauge and vernier callipers.
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AS Physics Wednesday 12th Sept.notebook
The Newton is a derived unit
November 12, 2012
The Newton in 'base units'
Remember: Dividing anything by a fraction is the same as multiplying it by the fraction turned upside down !
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AS Physics Wednesday 12th Sept.notebook
The joule is a derived unit
November 12, 2012
The joule expressed in 'base' units
You need to know the base units that make up the SI system of units together with the most common prefixes
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AS Physics Wednesday 12th Sept.notebook
November 12, 2012
The key formulae to find the volumes of standard shapes will be given to you in the exam - but you should know quite a few of these from your GCSE Maths
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AS Physics Wednesday 12th Sept.notebook
November 12, 2012
The number of decimal places given to a 'measurement' in physics in important. It lets other physicists and scientists know how precise a measurement has been e.g. 1m means the measuring device was able to measure only to the nearest m, meaning the answer could be 1m +/- 1m. A reading of 1.0 m, tells us that this measurement could be 1.0m A reading of 1.00m, tells us that this measurement could be 1.00m
+/- 0.1m +/- 0.001 m
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AS Physics Wednesday 12th Sept.notebook
The actual measurement
November 12, 2012
The uncertainty in the measurement made by a metre rule is +/ 1mm
The percentage uncertainty or error in this measurement is 12.5 %
Make sure the units are the same top and bottom
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AS Physics Wednesday 12th Sept.notebook
November 12, 2012
Measuring a small length using a metre rule gives a larger % error
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AS Physics Wednesday 12th Sept.notebook
November 12, 2012
Using a micrometer to measure small lengths
The sleeve reading is above 5.5mm and below 5.6mm
The reading on the thimble ( or second scale) is 32
Adding them together gives the final reading as 5.82 mm
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AS Physics Wednesday 12th Sept.notebook
November 12, 2012
Group answers to see if the 'foil' and block have the same density check on the Internet what the acceptable value for the density of aluminum is.
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AS Physics Wednesday 12th Sept.notebook
November 12, 2012
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