On Mon, 17 Jul 2006, Eugene Salamin wrote:
and is there an intuitive way to explain the conversion from the 30mph baseball's energy into kg*m^2/s^2 without calculus?
Perhaps, think of measuring the energy calorimetrically, by converting the energy into heat. Let a tank of water bring the baseball to a stop, and measure the temperature rise. This doesn't explain what energy actually IS; I can't think of a simple answer to that question.
The 30mph baseball is my favorite intuitive notion of energy. Batteries are another one I like to use when explaining it; compressed springs are good, too. I've used calorimetry examples as well, although those can be difficult since specific heat isn't as intuitive for people. What I was really trying to get at is that since momentum is, at least to me, a more intuitive way of understanding energy, why do we teach energy in terms of kilograms accelerated for a distance? And secondarily, what's the formula for converting a moving baseball into an accelerating kilogram, and how can I explain it to people who don't know calculus? -J