“Torque” isn’t just a terrible movie from 2004…

…it’s also an important concept that many of my physics students have studied recently.

Conceptually, torque is the quantity required to make an object rotate around a given point. I’m being very careful to avoid phrases like “how hard you have to turn something”, because there are ways to increase your torque without increasing the force you’re applying.

Distance from the point the object is rotating around is also a factor, as evidenced by the device I found in my parents’ kitchen.

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This photo is from Amazon, but I think my parents got theirs from the kitchen supplies equivalent of an Avon rep.

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Come for the cat video, stay for the science…

This showed up in my Facebook feed the other day.

As I watched this video about six or seven times in a row, you know I couldn’t help but consider the physics behind the poor kitty’s plight. We’ve discussed how an object only changes its motion (starts moving, stops moving, changes speed, changes direction) if an overall force acts on it. When a cat jumps off the floor, what’s applying the force that allows her to start moving upward?

Oddly enough, the floor is.

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I can sense you coming closer…

The science museum that I volunteer at recently opened up the traveling math exhibit that I’ve been looking forward to for a while. One of the activities features a piece of equipment that, as a physics student/teacher, is near and dear to my heart: the motion sensor. As you walk towards and away from the sensor, it records how far away you are and plots this distance on a graph.

It’s a nifty setup that gets people thinking about how motion can be described both visually and mathematically, but it does raise the question: how does the sensor know how far away you are?

The explanation is best illustrated with a game of catch.

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