Calculate the stored chemical energy per unit mass of  following foods in units of Btu per pound-mass. Then compare your re ult to the energy density of gasoline, expressed as a ratio ( energy/food energy). An approximate value for the energy density of is 20,000 Btu per pound-mass. One food calorie (or large calorie) is equivalent to 4184 joules. One ounce (mass) is 1/16 of a pound-mass.

A. A 2-ounce serving of sourdough bread containing 140 food calories.

B. One Hostess Twinkie with a mass of 1.5 ounces and containing 290 food calories.

C. An 8-ounce (mass) broiled sirloin steak containing 414 food calories.

D. A one-cup serving cup of green string beans with a mass of 4.4 ounces and containing 44 food calories.