Lesson 5.1 - Heat Transfer Technologies

You use many technologies to reduce or increase heat transfer.  People are often unaware that they use technologies because the technologies are taken for granted.  Cooking utensils, furnaces, refrigerators, convection ovens, microwave ovens, and radiators are examples of these technologies. 

Read Heat Transfer and Technologies on pages 98 and 99 in your textbook to learn about some heat transfer technologies and how they work. Then, answer the following questions.

Question 1. How is soup heated in a pot on the stove?

Question 2. Why are the handles on metal cooking pots made of plastic or wood?

Question 3. What kinds of heat transfer are involved when food is cooked in an oven?          

Question 4. Why do people in hot climates often wear white clothes?

Question 5. For what kinds of fires does Alberta have a worldwide reputation of expertise in extinguishing?

Check your answers with those that follow.

 

 

 

 

 

 

 

 

 

 

 

Answers to Questions:

Question 1. How is soup heated in a pot on the stove?

The pot is first heated by conduction of heat from the hot element on the stove that is in contact with the bottom of the pot. The soup is then heated by conduction of heat from the hot bottom of the pot that is in contact with the soup at the bottom. Convection currents are started in the soup that is heating from the bottom.  The convection currents heat the soup to a uniform temperature.

Question 2. Why are the handles on metal cooking pots made of plastic or wood?

Plastic and wood are poor conductors of heat and are used as handles so they do not get hot enough to burn your hands.

Question 3. What kinds of heat transfer are involved when food is cooked in an oven?   

All three kinds of heat transfer are involved when food is cooked in an oven.  They are conduction, convection, and radiation. 

Question 4. Why do people in hot climates often wear white clothes?

The Did You Know? on page 99 tells you that light-coloured surfaces reflect more heat than dark surfaces.  Thus, white clothing will reflect more heat and be cooler to wear than dark clothing.

Question 5. For what kinds of fires does Alberta have a worldwide reputation of expertise in extinguishing?

Career Connect on page 99 tells you that Alberta has a worldwide reputation for expertise in extinguishing chemical and oil fires. 

 


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