Slides in Heat
We have talked about different forms of energy now lets get more specific...
What is heat?
Solids are heated mainly by conduction. Conduction occurs between two objects that are touching. Conduction can also occur within an an object, such as a metal pot.
What happens when you heat a pan on a stove?
When a pan is heated on a stove the fast moving particles of the burner or flame hit the cooler particles of the pan. The collision gives the cooler particles more thermal energy. The particles of a pan start to move faster. Soon, the entire pan gets hot.
Another way to transfer heat is by convection. Convection transfers heat through liquid or gases.
If you want to boil water, you can heat it in post. As the pot heats, it transfers energy to the water. The water particles at the bottom of the pot heat first. They move faster and and farther apart. The hot water becomes less dense. The dense cooler water sinks, replacing the hot water. When all the particles of the water move at the same rate, the water boils.
The third way to transfer heat is by radiation. Radiation does not need matter to transfer heat. It can travel through space. Without radiation, energy from the Sun would not reach the Earth. Hot surfaces transfer thermal energy to the air by radiation.
Explain how do insulators and conductors work?
Cause and Effect: A metal object feels cooler than a wood object at room temperature. Why?
How is radiation different from conduction and convection?
How does heat change matter?
Think physical, chemical and changes of state.
Write a paragraph using lined paper. Compare a metal cup and a foam cup. Which would you choose for a hot drink? Which would you choose for a cold drink?
Explain your choices.
Draw a picture that shows examples of the three ways that heat is transferred. Add labels and captions to your picture.