A particular frost-free refrigerator uses about 745 kWh of electrical energy per year. Express this amount of energy in each unit. c. Cal

Verified step by step guidance

1. Identify the conversion factor from kilowatt-hours (kWh) to calories (cal). Note that 1 kWh is equivalent to 860,420 cal.
2. Multiply the total energy consumption of the refrigerator in kWh by the conversion factor to convert the energy into calories. Use the formula: Energy (cal) = Energy (kWh) \( \times \) 860,420 cal/kWh.
3. Set up the calculation with the given value: 745 kWh \( \times \) 860,420 cal/kWh.
4. Perform the multiplication to find the energy in calories.
5. Express the final result in calories, ensuring the correct number of significant figures based on the given data.

Key Concepts

Energy Units

Energy can be measured in various units, including kilowatt-hours (kWh) and calories (Cal). A kilowatt-hour is the amount of energy consumed when a device uses one kilowatt of power for one hour, while a calorie is the amount of energy needed to raise the temperature of one gram of water by one degree Celsius. Understanding these units is essential for converting energy values.

Conversion Factors

To convert between different energy units, specific conversion factors are used. For instance, 1 kWh is equivalent to approximately 860,420 calories. Knowing how to apply these conversion factors allows for accurate transformations between units, which is crucial for solving problems involving energy consumption.

Thermodynamics

Thermodynamics is the branch of physics that deals with heat and energy transfer. It provides the foundational principles for understanding how energy is converted and conserved in different systems. In the context of the refrigerator, thermodynamic principles help explain how electrical energy is transformed into cooling energy, which is relevant when discussing energy efficiency and consumption.