# CENTRIPETAL FORCE

See Introduction to CF Terms video https://pll.asu.edu/p/content/resource/Centripetal_Force_Introduction_Terms This is a one hour lesson on Circular Motion also called Centripetal Force. It is appropriate for 9th graders and older.

It can be used in front of the class or as a homework module. At the end of the lesson students should have :
1) Understood the three variables in the Centripetal Force equation.
2) Understood the relationship between the variables.
3) Repaired misconceptions associated with: a) how a bob will travel at the point of release, and b) the inversely proportional relationship between radius and centripetal force.

## Centripetal Force Research

The following research was funded by an NSF DRK-12 mechanism (1020367). The team researched how learning gains are affected by amount of embodiment in a lesson, and whether learning was also contingent on type of educational platform.

Six learning scenarios were created to address two misconceptions associated with circular motion and centripetal force

(i.e., objects have a circular impetus when released and that the amount of force is proportional to the radius of the circle).

The first factor in the experiment was the learning platform, with three levels:

1) SMALLab - large scale “mixed reality” immersive environment containing both digital and hands-on components ( see Figure 1)

2) interactive whiteboard (IWB) with a tracking pen (see Figure 2)

3) desktop computer with a mouse

The second factor was the degree of embodiment, with two levels :
1) low
2) high
This resulted in a 3 X 2 design.

Figures 1 and 2 represent the high embodied versions of the lessons because students are actually manipulating or moving the real swinging bob or a virtual version of the bob. In the low embodied conditions students merely tapped on digital icons to either start or stop simulations.

Pretests, immediate posttests, and one-week followup tests were administered to Psychology 101 students who were randomly to assigned to one of the six conditions Regardless of condition, participants made significant gains in learning from pretest to posttest. There were no significant main effects or interactions due to platform.

However, we found that the level of embodiment in the lesson predicted learning gains on the delayed test. These significant differences where seen on the generative items of the test. Half the test items (n = 14) were generative and required participants to draw vectors, answer with constructed text, etc.

The take home message is that when principles of embodiment – being active and generative – are designed into multimedia lessons students retain the content for longer. We remind instructors that sometimes the differences associated with learning in an embodied manner are not readily evident immediately after instruction, but only show up later. Manuscript currently under revise and resubmit.

### Table of the six Centripetal Force conditions.

 Platform Desktop Interactive Whiteboard SMALLab Embodiment Low Small screen, observe simulationsControl ‘bob’ speed with mouse on slider Large vertical screen, observe simulationsControl bob speed with pen on slider Large floor projection, observe simulationsControl bob speed with wand over slider Embodiment High Spin simulated ‘bob’ with mouse, mediated feedback Spin simulated bob with interactive pen, mediated feedback Spin real bob physically, receive both mediated and kinesthetic feedback

Gains on the three Centripetal Force Tests

Results

All six groups demonstrated significant gains in learning by posttest, F(1, 99) = 459.89, p < .001.

Interestingly, the participants in the High Embodied conditions RETAINED information longer.

There was a statistically significant interaction between embodiment and time on generative items between the invariant post and followup test. F (1, 62) = 4.83, p = .03.

Created with DRK-12 Grant