Newton's Third Law Vignette
This vignette features "person-on-the-street" interviews about forces in collisions as a function of the relative speeds and masses of cars. The viewers are shown various video segments of colliding carts with same and different masses and asked about forces. Over 90 percent of the participants believe that faster objects with more mass exert more force. Viewers are then shown video segments of a real car collision. The dynamics cart collisions with force sensor graphs show that the forces are equal in magnitude, even though a Lego passenger on a less massive cart suffers more injury.
Impact on Learning:
This vignette was studied and found to have a significant effect on learning. See Research Outcomes
Student Comments:
This activity helped me to reinforce the counter-intuitive idea that a more massive car colliding with a less massive car exert forces that are equal in magnitude relative to one another. Thanks!
Very clear. I understand the concepts and I think I will remember them because of the examples.
I enjoyed the video of the real car crashing. It made it very realistic.
It makes total sense.