Recently I sat at the table eating dinner, when I noticed a flutter in my peripheral vision, drawing my attention. I turned my head to see my cat batting at a cat toy someone had hung from the table...one of those sticks with the string attached and a feather or fluffy thing at the end, ya know? You wave it around like a wand and your cat pounces after it?
Anyway, someone in my family had set it up so just the string and attached feather hung down over the table, just within my cat's reach. She batted at it playfully.
It was then that I realized...hey! More real-life physics applications! This cat toy was an example of a pendulum!
When we learned about pendulums, we learned that they have a period of oscillation, or time it takes for them to complete one cycle, to swing forward and back to its original position. We learned that pendulum's periods of oscillation DO NOT depend on the mass of the object at the end of the pendulum (as with springs), but rather only depend on the length of the pendulum and the acceleration due to gravity.
For a perfect pendulum (weightless string, perfect conditions, etc), the equation for the period is T = 2(pi)radical(L/g), or 2 pi times the square root of length of the pendulum over acceleration due to gravity.
Unfortunately, my cat's toy wasn't a perfect pendulum, and the feather at the end inhibited the period time due to the air resistance it created...but oh well, she didn't seem to mind.
Thanks for reading!
Until next time,