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UFM A6 Video Clip 1: A group discusses their initial ideas
The group initially agrees that the soccer ball and the bowling ball would hit the ground together because the forces acting on them would have the same strength. Deb then explains why this inconsistent with what they have learned in the unit so far, but they still decide to go with their initial thinking.
UFM A6 Video Clip 2: Another group discusses their initial ideas
The group discusses whether the strength of the gravitational force changes as an object gets closer to the ground. They base their argument that it does on their thinking about gravitational potential energy (that they saw in Unit PEF). Linda admits that it may be different for force.
UFM A6 Video Clip 3: A class presents their initial ideas
The instructor sets out the format for the group presentations and then several groups present their thinking. It is evident that there are many different ideas present in the class, so the instructor summarizes them at the end of the presentations.
UFM A6 Video Clip 6: A group performs the experiment in Exploration #1
By dropping their own spheres, and also watching other groups drop theirs, the group tries to decide if the relative masses of the spheres make a difference as to which one hits the ground first. They are not absolutely sure, but Linda points out that since it is not clear, they should assume that they fall the same, regardless of mass.
UFM A6 Video Clip 9: A group discusses Summarizing Question S2
In discussing the falling carts in question S2, Rose initially proposes that the gravitational force is the same for both carts because they fall together. Linda tries to explain why the force on the 6 kg cart must be stronger and then helps Mary in representing this on the force diagrams.
UFM A6 Video Clip 10: A group discusses Summarizing Questions S2 and S3
In discussing the falling carts in question S2, the group seems to understand that the strength of the gravitational force depends directly on the object’s mass and prepare their whiteboard accordingly. However, in briefly discussing question S3 (what would happen if the gravitational forces were the same on both balls), Gail seems to revert to her earlier way of thinking.
UFM A6 Video Clip 11: A class discusses Summarizing Question S1
In discussing question S1, Group 2 argues that for the soccer ball and bowling ball to hit the ground at the same time, they must have different strength forces acting on them. Group 6 disagrees, arguing that since the they fall together, the forces acting on them must be the same. In the ensuing discussion, it becomes evident that Group 6 are actually confusing the gravitational force with the acceleration due to gravity.
UFM A6 Video Clip 1: A group discusses their initial ideas