Photo Shows the Demo Carts Used by the University of Texas at Austin.

• Medicine ball weighs about 15 lbs and is either thrown towards someone sitting on the skateboard - or -
  is thrown by that person.

• With two skate boards and a rope:
  
  Have two students kneel or sit on the long board at one end of the rope.
  Plus a single person on the small skateboard at the other end of the rope.
  Now have the single person on the small skateboard pull on the rope.

The image below is from our early website in 1995, courtesy of the University of Minnesota.

The Video Below shows the Demonstration in use at the University of Texas at Austin.

Last Updated 2/27/2018 - University of Texas at Austin Physics Dept. - All Rights Reserved.