Tag Archive | Newton’s 3rd Law

Day 53: Visualizing Newton’s 3rd Law with Colliding Carts

College-Prep Physics: We’ve been looking at how objects interact when they are at rest. But how about when they are moving? Do interacting objects still exert equal force on each other? I’ve posted about this demo before, but the quality of the video was lacking. So I’ve got better camera and a better table. Enjoy!

UPDATE: I’ve gotten requests for access to the raw videos for video analysis purposes. You can access all the videos here: http://bit.ly/collidingcarts2014

Some useful data for video analysis:

  • Frame rate = 220 fps
  • Length of table = 1.825 m
  • Length of cart = 0.223 m
  • Mass of cart = 0.786 kg
  • Mass of green College Physics textbook = 2.251 kg
  • Mass of Matter and Interactions textbook = 2.303 kg


Day 32: Friction and Newton’s 3rd Law


College-Prep Physics: Why doesn’t the wood block slide to the right? Why doesn’t the cart roll to the left? A great demo showing that friction acts on both the block and the cart, equally.