I received the following email from Mr. Burton after the publication of the previous post. I erroneously referred to the tennis ball as having a weight of 57 grams. I’m still not entirely certain why I was wrong, but I’m willing to accept the word of the weights and measures expert.
Amanda [Ms. Harrington],
The unit “gram” measures mass, not weight. You could say a weight of 0.56 N (the ‘N’ represents the unit of force called a newton) or you could say a mass of 57 grams. Though many in Europe errantly refer to their weight in kilograms, they are actually measuring their mass and using the term incorrectly. It is one of the few battles in the unit war where the metric system has gone awry.
Your Friendly Physics Geek,
Allen [Mr. Burton]
Editor’s Note: This is what it’s like in the office after all the students leave. Just a constant academicapalooza.