Let’s see how much you’ve picked up with these experiments and the reading – answer as best as you can. (No peeking at the answers until you’re done!) Just relax and see what jumps to mind when you read the question. You can also print these out and jot down your answers in your science notebook.
Click here for a printer-friendly version of the Unit 9: Light & Lasers Exercises.
Let’s see how you did! If you didn’t get a few of these, don’t let it stress you out – it just means you need to play with more experiments in this area. We’re all works in progress, and we have our entire lifetime to puzzle together the mysteries of the universe!
Here’s printer-friendly versions of the exercises and answers for you to print out: Simply click here for printable questions and answers.
1. Light can change speed The word “LASER” stands for Light Amplification by Stimulated Emission of Radiation.
2. Light from a regular incandescent light bulb covers the entire spectrum as well as scatters all over the room. A laser beam is monochromatic – the light that shoots out is usually one wavelength and color, and is in a narrow beam.
3. Glass (like a window pane) and clear plastic (like a water bottle).
4. Take it in a steamy room, like just after a hot shower. Or aim it through a glass of water that has a drop of milk in it.
5. The laser beam hits a spinning mirror that’s off-center. The more angled the mirror mount, the larger the image that the laser traces out. Which is why this is a perfect project for kids – the sloppier they build it, the better the laser light show.
6. High-power CO2 lasers have an intense amount of heat that melts through metal. These aren’t the lasers we’re going to be working with! The lasers at the grocery store are Class I lasers, which will harm your eye if you stare into it without blinking once for at least 15 minutes. These ‘keychain’ lasers are Class II & III, some of which can overpower your retina in less than a minute, and the damage is irreversible. When I work with kids in a live Laser Lab class, I have a zero-tolerance rule (which is explained beforehand): if misused, I just walk over, take the laser without a word, and keep it. Class proceeds as normal, and it’s up to the kid to figure out how to finish the project.
