A series of experiments about electricity and magnetism that was designed for use in the fourth grade.
BackgroundInvisible electrical charge can build up on objects that rub together. Sometimes this happens to clouds. The discharge can go unnoticed or be spectacular like lightning.
Materials Needed2 plastic stick pens
1 piece of wool
12" of string tape
Procedure1. Pull two desks apart and put the ruler between them. Tie the string around the middle of one pen and tape it in place. Use the string to hang this pen from the middle of the ruler. The pen should not be touching either desk.
2. For the rest of this experiment if you are asked to charge a pen, hold it by its cap and rub it briskly 50 times with the piece of wool. If you are asked to discharge a pen, roll it gently between your hands a few times.
3. Discharge both pens. Hold the loose pen by the cap and slowly bring it near the other pen. Observe what happens and record this in the chart on the next page.
4. Now charge the loose pen. Hold it by the cap and slowly bring it near the other pen. Observe what happens and record this in the chart below.
5. Discharge the loose pen. Now record what happens when you bring it near the other pen?
6. Charge both pens. Record what happens when you bring them near each other.
7. Discharge the loose pen but leave the hanging pen charged. Record what happens when you bring them near each other.
ConclusionIf two objects are charged the same, they _____________________ each other. If they are charged differently, they _____________________ each other.
Posted by Jay Roberts at 04:11 AM | Permalink