1. DAILY QUESTION
February 11, 2009
What is specific heat?

2. Agenda 2/11/09 Daily Question Ch 13 Section 2 Notes Assignments:
Assignments:
1. No assignment for tonight

3. 3 Ways of Heat Energy Transfer
Conduction
Convection
Radiation
A campfire is the perfect example!  Figure 6

4. Conduction
Takes place when two objects that are in contact are at unequal temperatures

5. Convection
The movement of matter due to differences in density that are caused by temperature variations
Only possible if the substance is a fluid
A liquid or gas

6. Convection Currents
The cycle of a heated fluid that rises and then cools and falls

7. Radiation Energy that is transferred as electromagnetic waves
Differs from conduction and convection
It does NOT involve the movement of matter

8. Conductors
Any material through which energy can be easily transferred as heat
Good conductors: metals
Insulators
Any material that reduces the amount of energy that can be transferred
Poor conductors: wood, rubber

9. Specific Heat
Describes how much energy is required to raise an object’s temperature
A characteristic physical property
Represented by c
Table 1 shows specific heats

10. Specific Heat Equation
Energy = specific heat x mass x temp. change
Energy =cm∆t

11. Practice Problem
How much energy must be transferred as heat to the 420 kg of water in a bathtub in order to raise the water’s temperature from 25°C to 37°C?