Sunday, August 20, 2017

What's the big deal with units?

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Mistakes when working out problems in physics have two common sources: signs (forgetting a number is negative) and units (e.g. using a numbe...
Wednesday, October 14, 2015

Is Superman gentle enough in catching Lois when she falls off a tall building?

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Did you notice how  you had to "give in" when catching a ball to reduce the force from the impact? Giving in helps to give more ti...
Thursday, March 20, 2014

Why do thunderbolts zigzag?

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Lightning bolts strike the ground at right angles and they also leave the clouds at right angle because both are conductors (in that context...
Thursday, March 6, 2014

Why is it easier to float in salt water?

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The short answer is "because salt water is denser than fresh water". That begs the question "so how does that help floating?...
Wednesday, February 19, 2014

Dad, I'm hungry! Why is the spaghetti taking so long to cook?

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Growing up in Switzerland, pasta came with a special set of instructions on the box for cooking at higher elevation. Pasta is cooked by im...
Saturday, September 14, 2013

Why do dogs (and cats) pant when they are hot?

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Cats and dogs can't sweat like we do to keep cool.  Sweating is an effective way of cooling down the body. It utilizes the difference i...
Friday, July 12, 2013

Why is it deadly to hit concrete when falling from a high place?

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This one goes back to a central concept in physics called the impulse-momentum theorem. The impulse momentum-theorem relates a change in vel...