PBL Project

Background Information

• Heat Transfer is the discipline of thermal engineering that concerns the generation, use, conversion, and exchange of thermal energy and heat between physical systems.

• Thermal Conductivity Heat transfer occurs at a faster rate in objects with a higher thermal conductivity. Heat transfer occurs at a slower rate in objects with a lower thermal conductivity.

• Thermal Energy is the part of potential energy and kinetic energy of an object or sample of matter that results in the system temperature.

• Heat Conduction: transfer of thermal energy between neighboring molecules due to a temperature gradient.

• Fourier's Law: The law of heat conduction which is called Fourier’s Law states that the time and rate of heat transfer through a material is proportional to the negative gradient in the temperature and to the area, at right angles to that gradient through which the heat is flowing.

• Newton's Law of Cooling: The Newton’s Law of Cooling states that the rate of heat loss of a body is proportional to the temperature difference between the body and its surroundings.

Question

Why does one ice melting block melt faster than the other?

Materials

• Pasco Ice melting blocks with O-rings

  • Ice

Procedure

1. Place the two blocks onto the table.

2. Label the one that felt cold, and the one that felt warm.

3. Put the rings on them, so that the water will not drip on to the table.

4. Now get two pieces of ice, and place them both on the blocks at the same exact time.

5. Observe the rate at which the ice melts on both of the blocks.

Summary of Experiment

In my project, I am testing the thermal conductivity of two blocks made of different materials. One of the blocks is made of aluminium and the other block is made of wood. They both have different thermal conductivity rates, so the time required for the block of ice to melt depends on the certain block that you place it on. Whenever you place the ice on the aluminium block, it melts at an extremely fast rate because it is a very good thermal conductor. Whenever you place the ice on the wooden block, it melts at an extremely slow rate because it is not a very good thermal conductor.

Scientific Principles

There are three main principles that are proven in this experiment.

1. Heat moves through a material at a specific rate. The rate it travels depends on the material itself: some materials allow heat to move quickly through them, some materials allow heat to move very slowly through them.

2. When two objects of different temperatures are put in contact with one another, there is an exchange of thermal energy. This exchange, known as heat conduction, causes the warmer object to cool and the cooler object to warm.

3. Everything in the room is the same temperature.