This Lesson Starter begins with some archive film in black and white of a demolition ball demolishing houses. After a while we cut to the 'professor'. He is dodging what looks like a demolition ball that is swinging from side to side across the frame in a menacing fashion. Will it hit him? Can he dodge out of the way quickly enough? But suddenly the professor catches the ball and reveals that it is not a spherical ball, but a 2D circular shape after all. It is not as dangerous as it first appeared. The learning objective is that children can describe how an object might be stopped and why it is dangerous to stop some moving objects. PROMPT QUESTION: Why could the professor safely stop the moving object?

Video Series: Lesson Starters
Release Date 2009