Patent ID: 6582234
Filing Date: 2003-06-24
Classification: G09B

Abstract:
A method for demonstrating the inverse square law, comprising:(a) providing a system for demonstrating the inverse square law, including: a variable torque pulley for demonstrating the inverse square law, said variable torque pulley including: a spiral member having a first central axis and a first perimeter, a first line-receiving groove disposed around said first perimeter, and a distal end; said first perimeter defined by an equation D&agr;1/&thgr;2, where D is a distance from any point on said first perimeter to said first central axis, and &thgr;2 is the square of an angle &thgr; formed by (1) a line between said point D and said central axis, and (2) a reference line; a circular member having a second central axis and a second perimeter, a second line-receiving groove disposed around said second perimeter; said spiral member connected to said circular member so that said first central axis is coincident with said second central axis; a counter weight connected to said circular member, so that a center of gravity of said variable torque pulley aligns with said first and second central axes. an axle disposed along said first and second central axes so that said variable torque pulley may rotate around said axle; a weight; a first line having a first end and a second end; a second line having a first end and a second end; a force measuring device having a first end and an opposite second end; (b) connecting said first end of said first line to said distal end of said spiral member; (c) connecting said second end of said first line to said weight; (d) connecting said first end of said second line to said second perimeter of said circular member; (e) connecting said second end of said second line to said first end of said force measuring device; (f) placing said second line in said second line-receiving groove and wrapping said second line around said second perimeter of said circular member; and, (g) pulling said second end of said force measuring device, thereby causing said variable torque pulley to rotate about said axle, and causing said first line to be received by said first line-receiving groove and wrap around said first perimeter of said spiral member and thereby lift said weight, and causing said force measuring device to measure a force.