Forces, Energy, Work, and Motion

CONCEPTS: This set of activities will consider one of the most basic concepts of physics: force. We'll talk about the forces we encounter most frequently--gravity, force of support, and friction--and then discuss and investigate how forces can CHANGE MOTION. We'll also investigate work and energy and show how forces acting can change energy from one form to another.

A. With younger children (K-2) the investigations will concentrate of energy changes when balls or marbles roll down ramps of different slopes or heights onto different materials. We'll divide the class into groups and each will investigate a different INDEPENDENT VARIABLE (aspect of the system that is changed on purpose, such as height of the top of the ramp) and its effect on the DEPENDENT VARIABLE of choice (another aspect of the system that is observed to see if it changes, such as the distance a ball rolls from the bottom of the ramp before stopping) while all other aspects of the system (such as slope of ramp, material on which the ball rolls, type and size of ball, etc.) are kept the same. All groups will present their results and explain them.

Materials and facilities to be supplied by class for Motion A: pencils or pens and paper to record results, classroom or corridor floor spaces--covered with different materials (carpet, tile, wood, etc.)--in which to work.

B. With older children (grades 3-5) we'll consider friction in detail and create a numerical factor to describe how much sliding friction there is between surfaces. We'll investigate ordinary materials to determine pairs produce the best and worst traction.

Materials and facilities to be supplied by the class for Motion B: pencils or pens and paper to record results, hard-cover books (as large as possible), sheets of various materials (towelling, foil, plastic wrap, etc.)