Physics 11 – Ok, they’re not the greatest photos in the world, but you get the idea!
Today students conducted the experiments that they designed last class. A few groups still did not see that they should be measuring force directly in order to find friction. However, most groups were reasonably efficient in collecting enough information in order to determine if their test variable had any effect on friction.
One of the variables that is a bit more difficult to test is object speed. Moving a wooden block at different speed gives some variability in measured friction. I think this is partly due to the students’ experiments which have the blocks moving very slowly. In these cases, you can see that the blocks are moving in and out of static and kinetic friction. It was very cool to see some groups clearly state that they thought the friction changed depending if the block was moving or not.
The students did not do a quantitative lab for finding the coefficient of friction, for this activity it was enough to see if there was an effect or not. I think we will do a quantitative lab as an assessment for lab skills.