1. Heat As Energy Transfer
SI Unit of heat: Joule (J)
Definition of heat:
Energy that flows from a higher temperature object to a lower temperature object
The sum total of all the energy of all the molecules in a substance is its internal (or thermal) energy.
Temperature: measures molecules’ average kinetic energy
Other common heat units: 1 calorie (cal) = J

3. Heat As Energy Transfer
(c) Specific heat
of the material
(Q) Thermal
energy added
(m) Mass of
the object
(ΔT) Change in
temperature m

5. Heat As Energy Transfer
Problem:
A 50 g piece of cadmium is at 20 oC. If 400 J of heat
is added to the cadmium, what is its final temperature

6. Heat As Energy Transfer
Problem:
A 100 g lead bullet traveling at 300 m/s is stopped by a large tree. Half the kinetic energy of the bullet is transformed into heat energy and remains with the the bullet while the other half is transmitted to the tree. What is the increase in temperature of the bullet?

7. Heat As Energy Transfer
Problem:
A 3.0 kg block of iron is dropped from rest from the top of a cliff. When the block hits the ground it is observed that its temperature increases by 0.50 oC. Assume that all the potential energy is used to heat the block. How high is the cliff?

8. Heat As Energy Transfer
Problem:
A 1.5 kg copper block is given an initial speed of 30 m/s on
a rough horizontal surface Because of friction, the block finally comes to rest. If the block absorbs 85% of its initial kinetic energy in the form of heat, Calculate its increase in temperature?