Click on the link below to PhET Forces and Motion: Basics.
https://phet.colorado.edu/sims/html/forces-and-motion-basics/latest/forces-and-motion-basics_en.html
You want the PhET lab with the tug-of-war.
Click on the "Net Force" lab.
You may do the other labs and the Energy Skate Park once you finish the assigned lab.
Click here for the Energy Skate Park simulation:
https://phet.colorado.edu/sims/html/energy-skate-park-basics/latest/energy-skate-park-basics_en.html
