Monday, September 29, 2003

How Strong Are Magnets?

Such a fun activity today! We did a mini-lab, measuring the strength of magnets. Basically, each group of kids balanced a tongue-depressor across two plastic cups, then put a magnet in the center of the tongue-depressor. They bent a large paper clip into a hook, and hung it underneath the tongue-depressor, attached only by the magnetic attraction. Then they put washers onto the paper clip, one at a time, measuring how many washers the paper clip could hold. They repeated this with 2, 3, 4, and 5 magnets, then graphed the results.

Everyone had a blast. Kids did their own little experiments with the magnets as they worked, discovering many interesting things: that they could use the repellent force of magnets to make the tongue-depressor fly off the cups, that their jewelry would stick to the magnets, that you could use one magnet to make another magnet "dance" on the table top.

The main point of this experiment, besides exploring magnetism, was to identify the independent and dependent variables, and which factors needed to be held constant to make the experiment work. I am looking forward to more experiments like this in the next few weeks!

On the other hand, one of my students stole two of my magnets this morning. I trust my students and have never had problems with theft in my new school (I had occasional problems in my old school). The VAST majority of students are honest, and I am very careful about my materials and set a tone of taking responsibility for them. They know that I will know if things are missing, and the fun will stop. Nevertheless, during first period I let a student distribute ten magnets to each table. At the end of the period, a student came up to me and said, "Oh, by the way, we only had 8 magnets at the start of the period, we were trying to tell you." Now, it seemed a little suspicious, but I couldn't be sure. Then, we were lined up in the hallway and another boy "found" a magnet dropped by the boy in front of him. First he named names, then he retracted. At this point, I gave the class a lecture about trusting them, but needing all my materials... if they accidently took any magnets, please return them, no questions asked. Nothing. I mentioned the incident to a colleague. Sixth period, she spotted a magnet in the hands of the same boy who had probably dropped the first one in the hallway. Hmmph. He will be sitting in another classroom doing book-work for the rest of the week, until I get the point across. Very disappointing.

Lab Report Update: 85 down, 25 to go. Handed them back in three out of four classes today. Final drafts due Friday.

0 Comments:

Post a Comment

<< Home