Specific Heat Worksheet Answer Key: Quick Reference Guide
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Understanding specific heat can often seem overwhelming, especially when it comes to homework assignments or exam preparation. This guide will provide you with a concise answer key for specific heat problems, breaking down the concepts in a way that's easy to understand. 🚀
What is Specific Heat?
Specific heat is defined as the amount of heat required to raise the temperature of one gram of a substance by one degree Celsius (°C). This property varies for different materials and is essential in various scientific calculations, particularly in thermodynamics.
The Formula
The formula for calculating the amount of heat (q) absorbed or released is:
[ q = m \cdot c \cdot \Delta T ]
Where:
- q = heat energy (in joules)
- m = mass (in grams)
- c = specific heat capacity (in joules per gram per degree Celsius)
- ΔT = change in temperature (final temperature - initial temperature)
Units of Specific Heat
- J/g°C: Joules per gram per degree Celsius
- Common substances and their specific heat values:
| Substance | Specific Heat (J/g°C) |
|---|---|
| Water | 4.18 |
| Ice | 2.09 |
| Copper | 0.39 |
| Aluminum | 0.90 |
| Iron | 0.45 |
Sample Problems and Answers
Problem 1: Heating Water
Question: How much heat is required to raise the temperature of 200 g of water from 20°C to 80°C?
- Given:
- m = 200 g
- c = 4.18 J/g°C (for water)
- ΔT = 80°C - 20°C = 60°C
Answer:
Using the formula: [ q = m \cdot c \cdot \Delta T ] [ q = 200 , \text{g} \cdot 4.18 , \text{J/g°C} \cdot 60 , \text{°C} ] [ q = 200 \cdot 4.18 \cdot 60 = 50,160 , \text{J} ]
Problem 2: Cooling Copper
Question: How much heat is released when 100 g of copper cools from 150°C to 50°C?
- Given:
- m = 100 g
- c = 0.39 J/g°C (for copper)
- ΔT = 50°C - 150°C = -100°C
Answer:
Using the formula: [ q = m \cdot c \cdot \Delta T ] [ q = 100 , \text{g} \cdot 0.39 , \text{J/g°C} \cdot (-100) , \text{°C} ] [ q = 100 \cdot 0.39 \cdot -100 = -3,900 , \text{J} ]
(Note: The negative sign indicates heat loss.)
Important Note
In calculations involving heat, it is crucial to pay attention to the direction of heat transfer:
- Positive q means heat is absorbed.
- Negative q indicates heat is released.
Practical Applications of Specific Heat
Specific heat has several practical applications in everyday life:
Cooking
Different cooking materials require different amounts of heat to change temperature, which is why some pans heat up quickly while others take longer.
Climate and Weather
Water's high specific heat capacity allows it to store large amounts of heat, influencing climate patterns and weather phenomena.
Engineering
In engineering and material science, understanding the specific heat of materials helps in designing thermal systems and materials that either retain or dissipate heat efficiently.
Conclusion
Understanding specific heat and how to solve related problems can significantly enhance your grasp of thermal physics. The worksheet answer key provided here serves as a quick reference guide to help clarify concepts and improve your problem-solving skills. Whenever you face specific heat calculations, remember to use the formula, identify the specific heat values of the substances involved, and carefully consider the temperature changes. Happy studying! 📚