Answer
a) 9 * 10^7 joules
b) 0.249 Cal
c) 1.31 * 10^-4 kWh
d) 1.1 * 10^4 cal
Work Step by Step
1 kWh = 3.6 X 10^6 joules; 1 cal = 1.162 X 10^-6 kWh; 1 kJ = 239 cal; 1 cal = 10^-2 Cal
We use unit conversions to obtain:
a) 25 kWh = 25 * 3.6 * 10^6 joules = 9 * 10^7 joules
b) 249 cal = 0.249 Cal
c) 113 cal = 113 * 1.162 * 10^-6 kilowatt-hour = 1.31 * 10^-4 kWh
d) 44 kJ = 44 * 239 calories = 1.1 * 10^4 cal