This is a demonstration and explanation of free fall. It demonstrates that in the absence of air resistance, an elephant and feather strike the ground at the same time. It includes some true/false statements with which you can test your understanding, as well as links to further resources, including relevant sections from other Physics Classroom tutorials. It also has a link to a demonstration of the same scenario, but with air resistance. (See Newton’s Laws: Elephant and Feather - Air Resistance.)
This is a good resource to use to help identify and address student misconceptions related to force, weight, gravity, mass, and acceleration. Use this with the accompanying demonstration about falling with air resistance (Newton’s Laws: Elephant and Feather - Air Resistance).