Physics 122 Weeks 2 & 3

Boyle's Law Apparatus

Ask your students to try and compress a syringe with a closed end. They will soon encounter resistance due to Boyle's law, which will give them a physical example to help support your explanation. **Press straight down and minimize any torque**

Steam Gun

This demonstration has some real pop! Show your students that heating a gas causes it to expand, and in a closed system can cause some explosive results.

Fire Syringe

This is another fun and exciting demonstration. After lubricating the piston and maximizing the cotton's surface area, you need to quickly, sharply, and without hesitation compress the piston straight down.

**Do Not Press At An Angle**

Hand Boiler and Pulse Glass 

Hold both objects at a 45 degree angle. When heat is applied to the bottom sphere it increases the internal pressure pushing the liquid into the top sphere.

**Do not use a hair dryer for the small hand boiler**

Mole Box

This box is the size a mole of gas would take up at S.T.P.

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3-D Phase Change Model

This 3-D model shows as much pressure, temperature, and volume information for water as you can fit in a confined area.

Atmospheric Pressure

Place suction cups or a rubber mat with a handle on top of a flat surface and have students try to remove it. Or, place two suction cups together and have students try to pull them apart. They will be pleasantly surprised by their results.

Magdeburg Plates

After fitting the two plates together use the hand pump to evacuate the air. Close the valve and detach the pump, then offer $50 to the first student who can pull them apart on their own without turning the valve. And then pop some popcorn!

Atmospheric Can Crush

Place a small amount of water in a can, and boil it on a hot plate. Once steam comes out, invert the can into a cold bath to watch our atmosphere do some work!

Atmosphere Bar 

This 1" by 1" steel bar represents the weight of one square inch of atmosphere when held upright.

Bi-Metallic Strip

When these metals are heated with a blow torch, their different expansion rates cause the metal to bend. Make sure to have a water source on hand in order to cool the metal down before placing it on a surface to rest.

Ball and Ring

Show your students that the ball easily fits through the ring before heating, but after the ball is heated it no longer fits. Make sure to have a water source on hand to cool the heated metal down to fit it back through the ring.

Wire Expansion

When you heat up the wire it expands, loosening the tension on the dial causing it to move. For a more dramatic effect, place the wire directly in the flame. 

Thermal Conduction Rods

Your students can feel conduction by holding onto metal bars as you blow torch them on the opposing end and timing how long it takes them to heat up one at a time, or by feeling which one gets hot first if holding them both in separate hands. **Have a water bath to dunk rods nearby**

Chimney Model

This demonstration is nothing more than a small chimney. Without the vane to allow air circulation the flame burns out. Once air is circulating you can blow out a match and bring it close to the tube, the smoke will then follow the convection current!

Convection Tube

By following some colored dye in water, you can show students that fluids convect. You can even reverse the flow direction by transferring which side of the tube the heat source warms.

Crook's Radiometer

The vanes on the radiometer are colored differently on each side. The black side will heat up more rapidly than the white side causing the vane to spin. See if your students can explain why the vane rotates knowing that it is not an example of the photoelectric effect.

Parabolic Reflector

Use this demonstration to show your students that radiation is a form of energy transfer by igniting a match using the IR radiation of a projector. **This demonstration is extremely bright. Bring sunglasses and tell your students not to stare directly into the focal point.**

Specific Heat Comparison

When two objects are heated by the same source for the same amount of time some students may believe that they should be the same temperature. Use this demonstration to show them that the material's specific heat influences how quickly it heats up!

Air and Water-Filled Balloons

This demonstration is another fun one that will keep your students engaged. Show them that the specific heat of water is quite large and why water takes so long to change temperature. Practice getting a water and air balloon before trying it in front of your students.