When a group of children attempt to move their play fort, they realize that six simple machines make the work much easier by changing either force or distance. They learn to identify real-world examples of simple machines including the lever, pulley, wedge, wheel and axle, inclined plane, and screw.
When "Hardware Hal" holds a "Simple and Compound Machines Sale" he demonstrates to his assistants the six simple machines: the lever, wedge, inclined plane, pulley, wheel & axle, and screw. Shows how these machines make work easier by changing force, direction, or distance.
Motion
Concepts and terminology discussed include: frame of reference, speed, velocity, acceleration, deceleration, momentum, and conservation of momentum.