WHEN IS AN OBJECT ACCELERATING? ENGAGE To engage students in the topic of acceleration, ask if they have ever ridden a roller coaster. Show a brief video or film clip showing a roller coaster ride. After the video, explain that objects that are changing their speed or their direction are said to be accelerating. The rate at which the speed or direction changes is referred to as acceleration...EXPLOREUse a modern version of Galileo’s experiment to learn about acceleration. Acceleration means a