Teaching Physics with the Physics Suite
Edward F. Redish
A small electric immersion heater is used to heat 100 g of water for a cup of herbal tea. The heater is labeled "200 Watts".
(a) Assuming you are doing this problem for an exam, make a number of simplifying assumptions that will allow you to calculate reasonably promptly how much time it would take to heat the water from room temperature (23 C) to just the perfect temperature for making tea (95 C). Specify the assumptions you have made.
(b) If you really care about this time, which of your assumptions would you think is the most important to take into account? Don't do a new calculation, but explain why you think the assumption you chose is the most significant.
Page last modified December 4, 2008: H&T07