Robert Krampf's Experiment of the Week
December 6, 2004 - This Week's Experiment - #415 Get a Bigger Handle
My niece and I had a wonderful week. We spent quite a bit of time on wildlife photography at the Merritt Island National Seashore. We also managed a trip to Busch Gardens, to visit a friend of hers. She has headed back to California, and I already miss having her to talk to. Hopefully, she will come back soon.
Today I am installing shelves in my bedroom, making room for more books. It is a well-known fact that you can never have enough books, and I do my part to keep the publishers and authors around the world in business. I am using wood screws to attach the shelving to the wall. When I switched to a different screwdriver, I got the idea for this week's experiment. To try this yourself, you will need:
a piece of scrap wood
a wood screw
several screwdrivers with different sized handles
Select the screwdriver with the largest handle. Use that one to start the screw into the wood. Pay attention to how hard you have to work to turn the screw. Then try the same thing with a screwdriver that has a thinner handle. What do you notice?
With the thinner handle, it is much harder to turn the screw. If you try several different screwdrivers, you will find that the thicker the handle is, the easier it is to use. If you have one of the screwdrivers with an interchangeable handle, try removing the handle and just using the shaft to turn the screw. This is MUCH more difficult.
Why does the size of the handle make a difference? A large handle is easier to hold on to, but there is more to it than that. You are working with a simple machine known as a wheel and axle. The handle is the wheel, and the shaft and screw are the axle. With this type of simple machine, the larger the wheel is, the easier it is to turn the axle. Why?
Think of the steering wheel on a car. The steering wheel is attached to an axle, which turns the wheels of the car. If you hold the outside of the steering wheel, it is easy to turn. Try doing the same thing by holding the center of the steering wheel. That takes a lot more muscle. The width of the steering wheel acts as a lever. If you have ever studied levers, you know that the longer a lever is, the less muscle power it takes to move. A wider wheel is the same as a longer lever. As with a lever, you have to move it farther, but it takes less brute force to move it.
If you have never studied levers, now is a good time. Stick a spoon into a carton of ice cream. Then use the handle as a lever, pushing down to push out a nice scoop of ice cream. You may have to try this for several scoops to be sure that you have it right.
Have a wonder filled week.
