Modern light sources are rated in lumens or, more importantly, lumens per watt. The first figure expresses the brightness of the source whereas the second indicates its efficiency. But what, exactly, is a lumen? To answer that question it is useful to recall that the first man-made light sources relied on heat and were very … Continue reading What are lumens?
SP8-9 Forces Doing Work (mini-test)
The first module of Y11 is now complete and to help you prepare for the assessment I have created a mini-test, complete with mark scheme and explanation. You can access the test by clicking here and the mark scheme is here. Work through the questions then check your answers to spot any errors or misconceptions … Continue reading SP8-9 Forces Doing Work (mini-test)
Mr Tarrant's physbang 'blog 