doriandreyfussappphysics

Applied Physics Blog

Month: December, 2014

For homework this weekend, do a little research about what a “simple machine is” (like 10 mins). Then, observe the world around you for the day. See how many you can find! Take some pictures Then, post these and write on your blog about what you found and how you think these machines make the tasks they are associated with easier (less effort etc.)

A simple machine is a mechanical device that changes the directions or magnitude of force. Some simple machines include levers, pulleys, inclined planes, wedges, screws, and wheel and axels.

Here are some examples:

unnamedThis is an example of a pulley. This makes pulling your shades up or down easier because you do not have to pull or push the shades themselves. Since the top of the fabric for the shades is so high up, it would make it very difficult to control the shades if you did not have the pulley device. unnamed-1This simple machine is an example of a screw. This device was attached to a drawer’s handles. It makes things easier because it keeps the handle on the dresser securely, which makes it easier to open drawers.

unnamed-2These stairs are an example of a inclined plane, which is a form of a ramp. They make getting to different floors easier because it enables people to actually reach other floors. Getting up and down would otherwise be impossible (excluding elevators).

unnamed-3The knife is an example of a wedge. The thinness and sharpness of the knifes makes cutting easier and cleaner.

Elasticity

post on your blog about the relative ELASTICITY of these two different balls. What makes them different? What do you think affects or changes their ability to deform and reform? What do you think this means in terms of energy transfer etc. Make some predictions!

Elasticity is defined as the ability of an object or material to resume its normal shape after being stretched or compressed; stretchiness. In both videos, the ball’s shape transforms. The first video of the bouncy ball seems to bounce and transform more quickly than the tennis ball. I think the material and the interior of the ball affects the two ball’s ability to deform and reform. Although the tennis ball solely encloses air and is made of rubber, the bouncy ball is completely made of rubber without any other materials to effect the bounce due to friction. I think the fuzziness of the outside of the tennis ball blocks or absorbs some of the energy from being transferred to the ground.