lonemorf Posted February 8, 2017 Share Posted February 8, 2017 Hi, Im feeling a little stupid - would someone care to educate me, so I can assist my frustrated daughter: Peter used 2 spotlights (one red, one green) to shine a mixture of red and green light on to some red curtains. 1. What colour did the red curtains appear in this light 2. Give the reason why they appeared this colour Thanks in advance. Link to comment Share on other sites More sharing options...
Kriivari Posted February 8, 2017 Share Posted February 8, 2017 Unless my physics is really rusty... 1. Red. 2. Red curtains absorb all other wavelengths except red, and as the incoming light does have the red wavelength, that is reflected, making the curtains seem red. See eg. http://www.physicsclassroom.com/class/light/Lesson-2/Light-Absorption,-Reflection,-and-Transmission Link to comment Share on other sites More sharing options...
lonemorf Posted February 8, 2017 Author Share Posted February 8, 2017 Perfect - my thoughts affirmed. :) Link to comment Share on other sites More sharing options...
gyro_gearloose Posted February 9, 2017 Share Posted February 9, 2017 And for bonus points if Peter had shone both lights at the same point on a white surface, the light would have appeared to be yellow. Heres why Link to comment Share on other sites More sharing options...
timsabre Posted February 9, 2017 Share Posted February 9, 2017 And for bonus points if Peter had shone both lights at the same point on a white surface, the light would have appeared to be yellow. Heres why You don't get bonus points in school homework any more I'm afraid. Thinking past the question in front of you is not to be encouraged apparently. (if you are really lucky then the question they are asking will not be dumbed down to such an extent that you have to give a wrong answer to get it marked right.example computer science gcse question my daughter had: What is a JPEG?Their correct answer: a picture fileMy answer.... well actually JPEG stands for Joint Photographic Experts Group and they created a way of compressing an image to store it in a smaller size etc etcbut they are not interested... ) Link to comment Share on other sites More sharing options...
alistermorton Posted February 9, 2017 Share Posted February 9, 2017 Shades of "What is a biro". Link to comment Share on other sites More sharing options...
lonemorf Posted February 9, 2017 Author Share Posted February 9, 2017 Thats great stuff - v.useful link too. As much as she wont get any "merit" for pushing the boundaries, she does want to learn more, and as she is "getting into lighting", this is actually doubly useful. Link to comment Share on other sites More sharing options...
ojc123 Posted February 9, 2017 Share Posted February 9, 2017 Every year I am asked by the physics staff to set up colour combinations for this kind of thing using the stage lighting in a blackout. Since the advent of LED fixtures it's been a lot more convincing (and a lot easier.) The students have been taught this stuff before they arrive but it still amazes them. I guess it's kind of counter intuitive. Link to comment Share on other sites More sharing options...
timsabre Posted February 9, 2017 Share Posted February 9, 2017 As much as she wont get any "merit" for pushing the boundaries, she does want to learn more, and as she is "getting into lighting", this is actually doubly useful. Well good for her and such interest is to be encouraged. Hopefully she has a teacher who will do the interesting extra stuff even though the government doesn't want them to. Link to comment Share on other sites More sharing options...
sandall Posted February 9, 2017 Share Posted February 9, 2017 [ Hopefully she has a teacher who will do the interesting extra stuff even though the government doesn't want them to...... do I detect a touch of early-onset cynicism.... ? Link to comment Share on other sites More sharing options...
timsabre Posted February 9, 2017 Share Posted February 9, 2017 ..... do I detect a touch of early-onset cynicism.... ? Unfortunately so. As a parent of 2 bright girls, I am rather disillusioned with our education system which appears to be only interested in teaching them how to pass an exam. Link to comment Share on other sites More sharing options...
lonemorf Posted February 9, 2017 Author Share Posted February 9, 2017 Yup I totally agree Tim. Extracurricular activity seems to be parent driven - the teachers are literally number driven now, and not a lot more. It is nice that she asks beyond whats in the homework - gives us a good excuse to bugger about with some tech and have her experiment and learn new things. Off the back of this homework, we are going to get 2 of our mac 250s out this weekend, and play with some colour filtering/mixing (going to have 1 powered up and putting out light, and one with a dead lamp, and the cover off, so she can see the colour wheels etc)Probably not the same effect as gels, but I think the principle will be there. Link to comment Share on other sites More sharing options...
Simon Lewis Posted February 9, 2017 Share Posted February 9, 2017 I had to be quietly restrained at times... I thought this little meme came close.... 1) Teaching Math In 1956 A logger sells a truckload of lumber for $100. His cost of production is 4/5 of the price. What is his profit? 2) Teaching Math In 1976 A logger sells a truckload of lumber for $100. His cost of production is 4/5 of the price, or $80. What is his profit? 3) Teaching Math In 1986 A logger sells a truckload of lumber for $100. His cost of production is $80. Did he make a profit? 4) Teaching Math In 1996 A logger sells a truckload of lumber for $100. His cost of production is $80 and his profit is $20. Your assignment: Underline the number 20. 5) Teaching Math In 2016 A logger cuts down a beautiful forest because he is selfish and inconsiderate and cares nothing for the habitat of the animals and the preservation of our woodlands. He does this so he can make a profit of $20. What do you think of this way of making a living? Topic for class participation after answering the question: How did the birds and squirrels feel as the logger cut down their homes? Link to comment Share on other sites More sharing options...
timsabre Posted February 9, 2017 Share Posted February 9, 2017 I would add that this is not a criticism of the teachers, some of whom really put in loads of effort (and extra working hours) to make it interesting. I don't know how they keep up the enthusiasm when they are judged on a page of numbers. Link to comment Share on other sites More sharing options...
paulears Posted February 9, 2017 Share Posted February 9, 2017 My 5 year old grandson has had a cough and didn't go into school today - Thursdays my wife (or me) take him to school, and collect him, however he'd been coughing all night, so my wife took his cousin to the same school as usual and told the teacher he'd been up all night and would be going to the doctors - she also asked the school if there was anything she could do at home as he hated missing his lessons - they would email something for over half term next week. While we were at the doctors the school phoned his mum at work and told her the absence was unauthorised unless she could get the doctor to not only confirm his attendance, but give details of the illness - and unauthorised means the dreaded bill for sixty quid. He is FIVE, and has a chest infection for Gods sake! Apparently, lots of parents take them out thurs/fri before half term for a linger holiday. I was furious. As an occasional supply teacher I see such dreadful lessons, dreadful attitude and no learning taking place at almost every school. The notion that they have the time to have somebody chasing invoices stinks. Link to comment Share on other sites More sharing options...
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