The Elephant on the Bridge/teaching approach
From OER in Education
An interactive method of exploring this activity might be to have the children, working in small groups(ta), build a rope/string bridge and use a model elephant to stand on it. The children could either observe what happens and then discuss it or could film it and watch in time lapse to see exactly where the movement occurs in the bridge/elephant system. The latter would assist them in considering the direction of the forces acting as they would be able to see the direction of movement very clearly.