Tuesday, April 22, 2008 - 4B

Density 2 Lab - Density of Irregular Objects

Students did Density Lab 2 - Irregular objects
Lab kits had cups of gravel, nails, metal wire, balsa wood, and BB's as well as a rock and a golf ball. Also in kit were a 200 mL beaker, a pipette, and a 10 mL graduated cylinder.

I described, using pictures, the two displacement methods to find volume:
Method 1 - objects fit into graduated cylinder
Method 2 - objects do NOT fit into graduated cylinder

If objects get stuck in the graduated cylinder, use forceps to remove them or call me. Do NOT bang the graduated cylinder against the table.

If the object floats, you need to push it down just below the water level and then read the graduated cylinder.

After finding volume using method 1, pour as much water as you can back into the beaker and then dump the object onto a paper towel. Dry off. Wipe out cup if wet and then put object back into cup.

Students posted values on board - redid trials that looked a bit off, and handed lab sheets into the bin.