Fast Fact:
Since the horrific crash and fire that killed drivers Dave McDonnell and Eddy Sachs in 1964, methanol has replaced gasoline as the fuel of choice at the speedway.
Objective:
The students will test the energy of different fuels.
In the Film:
Indy cars are fueled by an organic alcohol called methanol. More energy in each fuel cell means more speed on the track. How are different fuels tested?
Background:
When fuel is purchased it comes with energy already packed into the molecular bonds between the atoms. When this energy is released, heat is produced. Such reactions are exothermic. The amount of heat energy released may be estimated by measuring its effect on water temperature. Each gram of water requires 4.18 Joules (1 calorie) of energy to raise its temperature 1ÞC(1.8ÞF ). Heat can be used to do work such as powering machines.
Materials:
A tin can, a coat hanger, water, a thermometer, a metal bottle cap, an eye dropper, safety goggles, a lighter, fuels such as gasoline, ethanol or methanol. (If these are not available, then methyl hydrate, kerosene, white gas or alcohol can be used.)
To Do:
Bend the coat hanger into a stand that will hold the can over the bottle cap. (If you cannot get it to form a stable stand, place the bottle cap between two bricks and put the tin can on them.)
The students should be wearing goggles. Place a measured amount of room temperature water in the can. The amount should be the same for each trial: 50 to 100 cm3 should be enough. Measure the starting temperature of the water with the thermometer. Use the eye dropper to measure out a small amount of fuel into the bottle cap. The same volume of fuel should be used in each test. Taking care to observe all safety precautions, light the fuel. It will heat the water in the tin can. When all the fuel is spent, have the students measure the temperature of the water again. Ask them to calculate the temperature increase caused by the fuel. Repeat the experiment for each fuel. Which one warmed the water the most?
Whats Going On?
The temperature change of the water is directly related to the amount of energy it got from the fuel. The fuel that raised the temperature the most is the fuel that produced the most energy per unit of volume.
Taking It Further:
1. Have the students study the by-products of each of the burning fuels. Which one produced the most smoke? What would this smoke do to the inside of an engine? How would it affect the spectators?
2. Ask the students to research the power of the fuel used in the main engines of NASAs space shuttle and compare it to methanol. Note that the by-product of NASAs fuel is just simple, pure water!
3. Give the students the task of researching horsepower. Have them explain why engine horsepower does not necessarily produce greater speed in a modern Indy car. The CART regulations require engines to be equipped with a pop-off valve which limits the power the engines can generate.