Task 1a: How Light Travels
a) What is a laser? http://spaceplace.nasa.gov/laser/
b) Take a photo of the laser setup.
c) Write down how we revealed how the light from the laser travels.
d) What did we do to form shadows?
e) Why do the shadows form?
f) What effect does changing the size of the light source have on the shadow?
g) What effect does changing the position of the light source have on the shadow?
h) What is happening to the object that is causing the shadow?
Write these up for your portfolio – include all diagrams and photos.
Task 1b: Light Intensity
You are going to use a solar panel connected to a voltmeter to measure the intensity of light coming from a desk lamp as you move further away from it.
Remember to photograph the setup of equipment.
a) Write down the method you used (include a photo in your portfolio).
b) Make a table of results of distance and potential difference (voltage).
c) Draw a graph of your data.
d) When there is a higher potential difference, what is that telling you about the light intensity on the panel?
e) Describe in one sentence what your graph shows. It isn’t a straight line, it’s curved and shows an inverse square relationship.
f) What problem does our finding create when trying to light up objects on a stage? Go to the website below and read the article to find out more. Make sure your answer includes the term ‘fall-off’. We’ll look at some ways of solving this problem later in the course.