I have finished discussing the basics of simple machines with my grade 8 classes. We have looked at the formula for work, and their weekend homework task was to play on and explore the following websites:
Edheads (update – this game is no longer free, it now requires membership)
Museum of Science and Industry
This week we begin mechanical advantage. We will start by playing with levers (materials: prisms for fulcrums, metre sticks, spring scales, and various masses). The students will investigate what happens to mechanical advantage as we change between first, second and third class levers, exploring with various lengths of effort and load arms. We will then move on to pulleys, and the students will build various systems with fixed and movable pulleys (materials: pulleys, string, spring scales, various masses, and retort stands with ring clamps). They will explore different lengths of rope and how mechanical advantage changes depending on how the load is supported.
Here are some links that I will use along the way to supplement their learning:
Wisc Online – I will have to tread carefully with this one, as the units are not metric.
Pulley Basics (from an unexpected source: Summerlift Products)
Videos:
Mechanical Advantage (from Hila Road Outdoor Centre & Educational Resources)
Eureka Video Series (1980’s cartoon series from TV Ontario) – This is the first video in the work and mechanical advantage series, which include episodes 8 through 15. For more information on Eureka, see the Wikipedia Page.
Mechanical Advantage (from Khan Academy)
If you have any other good resources, I would love to see them.
Have a great week.
