NIAGARA FALLS Purpose: To observe the effects of thermal agitation on temperature. Equipment and Supplies: Blender (hand or electric - can substitute real quick stirring with a spoon) Thermometer (one used to take your temp or an outdoor thermometer or fishbowl one will work just fine) Discussion: When water flows over a waterfall, it loses PE and gains KE. As it crashes at the bottom of the falls, its KE is converted into heat. If all of the PE of the water is converted into heat, with no loss due to evaporation or by any other means, one kilogram of water that falls one meter increases its temperature by a little more than 0.002 C. To see why check the following calculation: PE = KE gained = Heat gained Therefore PE = Heat `gained mgh(in joules) ~ cmAT(in calories) If we express specific heat of water c in terms of joules (that is, 1 cal = 4.184 Joules), we can solve for AT. Then AT = gh C (9.8 , )(1m) AT = - 1 cal 8 C (9.8 ,)(1m) AT = 4.184- g C (9.8 , )(1m) AT = 4184 - kg C AT = 0.0023 C 1. How much would the temperature rise if 2kg fell one meter? 1 million kg? Show your calculations!AT1,000,000 = 2.Predict the temperature rise of water falling 50 meters over Niagara Falls. (In actual fact, the cooling effect of evaporation practically cancels this rise!) Show your calculations! Procedure: Simulate Niagara Falls with minimum evaporation by using a blender to heat water. Start by pouring about 200mL (use a pop can for measuring 2/3 Full) of (room temperature) water into a blender. Measure the temperature. Run the blender several minutes. Measure the temperature again. T : before after Summing Up: 3. Did the temperature remain the same? Why or why not? 4. Does blending the water for a longer period of time cause a greater increase in temperature? 5. Does the initial temperature of the water have an effect on the experiment