The previous post (Experimental Errors, https://physbang.com/2023/11/12/experimental-errors/) ended with an invitation to "consider whether there are any other, previously unidentified, sources of uncertainty" in the method used to derive the specific heat capacity of an iron block. As it happens, there are (at least) three possibilities that weren't covered in the original article. Firstly, there is … Continue reading Experimental Errors (part 2)
Experimental errors
Experiments are often used to confirm (or, more usefully, refute) particular ideas but their impact is limited by measurement errors that can compromise the results. The obvious answer is to reduce the uncertainties as much as possible but what do you do if this causes the result to move further away from the expected value? … Continue reading Experimental errors
Specific Heat Capacity and Energy Stores
Two ways are suggested in GCSE Physics for measuring the specific heat capacity of a material. I have already explained the electrical method (see here) but it looks likely, from the advanced information supplied by AQA, that the other method will feature in this summer's Trilogy physics examination. So here's what you need to know … Continue reading Specific Heat Capacity and Energy Stores
Molar Heat Capacity
There is a required practical in GCSE Physics courses, including Trilogy, that involves calculating the specific heat capacity of different metal blocks. This is done by measuring the energy supplied (using voltage, current and time) and monitoring the temperature increase. You are expected to recall this experiment and be able to suggest how it could … Continue reading Molar Heat Capacity
Phase-change diagrams
The concepts of specific heat capacity and specific latent heat are nicely illustrated in phase-change diagrams. But how realistic are the diagrams that are commonly seen online? The answer, perhaps surprisingly, is "not very". The phase-change diagram shown below is useful in terms of the amount of information it provides but, in common with many … Continue reading Phase-change diagrams
Energy: the biggest “big idea”
Physics, let alone all the sciences put together, covers such a vast range of knowledge that it's useful to identify a small number of "big ideas" that link across a greater number of concepts. And energy is undoubtedly the biggest of these "big ideas". When it comes to revising energy, the breadth of its impact … Continue reading Energy: the biggest “big idea”
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