When you come in…

1. Complete entry ticket

2. Copy down today’s homework

3. Take out the Greenhouse effect worksheet, heat study guide and heat technology poster

How do you think they work?

You park your car outside on a hot summer day. When you put on your seat belt, what do you feel?

The metal part gets hot enough

to burn you! The cloth stays

cool.

Specific Heat Capacity

Textbook definition: The amount of energy needed to change the temp. of 1 kg of a substance by 1˚ C.

In my own words: How easily something changes temperature.

High specific heat = hard to change its temp.Low specific heat = easy to change its temp.

Which one has the highest specific heat capacity?

Substance Specific Heat Capacity (J/kg °C)Lead 128

Gold 129

Silver 234

Metal of seat belt 500

Aluminum 899

Sand 800

Cloth of seat belt 1,340

Wood 1,760

Water 4,184

Example of specific heat capacity:

Why is it cooler at the beach in the summer?

Hint: Which has the higher specific heat capacity: the water or the sand?

Answer: Water has a high specific heat capacity, so the water stays cool longer than the land.

Heat Technology Refrigerators- Cooling

Takes Energy!

The refrigerator transfers thermal energy from inside the refrigerator to the condenser coils at the back.

This is why the back of a refrigerator feels warm!

Heat PumpsDevices that move thermal energy

from one location to another.

Example: Air Conditioner

Moves thermal energy from inside the house to the

outside

Wait? Doesn’t that go against the rule that heat always moves from hotter to colder?

Air conditioner

Answer: Yes, so it takes energy to do it!

Heat Engines – Machines that use heat to do work. They convert thermal energy into kinetic energy.

Heat Engines

Internal External

Internal Combustion Engine- Fuel burns inside the engine in chambers called cylinders.

Example: car engine

External Combustion Engine- Fuel is burned outside the engine. Example: steam engine