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 Table of Mechanics Mechanics (1K): Applications of Newton's Laws Mechanics (1M): Work and Energy Lecture Demonstrations

## Gravity

PIRA classification 1L

20 Demonstrations listed of which 9 are grayed out

 Grayed out demonstrations are not available or within our archive and are under consideration to be added.

# 1L10. Universal Gravitational Constant

 PIRA # Demonstration Name Abstract 1L10.10 Cavendish Balance Film Loop Time lapse of the Cavendish experiment. 1L10.20 Cavendish_Balance_Model A model of the Cavendish balance demonstrates the basic ideas behind this important experiment. 1L10.30 Cavendish Balance Standard Cavendish experiment with lead balls and optical lever detection, mounted permanently in the classrooms. Adjust hours before the experiment. 1L10.34 Cavendish Balance Wire Replacement Use amorphous metallic ribbon as a wire replacement which gives a higher spring constant and is more durable. See AJP 55(4),380. 1L10.36 Modified Torsion Balance A very small suspension wire is used allowing the linear accelerations to be measured directly. See AJP 57(5), 417. 1L10.42 Servo Mechanism Cavendish Balance The torsion bar does not appreciably rotate. A simple electronic servomechanism is used to maintain rotational equilibrium as an external mass is introduced. The resulting servo correction voltage is proportional to the torque due to gravity. This effect can be observed in tens of seconds. See AJP 51(4), 367.

# 1L20. Orbits

 PIRA # Demonstration Name Abstract 1L20.10 Rubber_Membrane Deform a rubber membrane with a lead ball resting at it's center, representing a potential well. Marbles are then sent slightly off center which follow the warps in the membrane. 1L20.12 Gravity Well on Overhead Projector Making a Lucite 1/R surface for use on the overhead projector. 1L20.14 Elliptical Motion A ball rolling in a funnel or cone. See Sutton M-131. 1L20.16 Gravity Surface Using the Playskool drum as a gravity surface. 1L20.17 Orbits in a Wineglass A properly shaped wine glass is used with ball bearings to show radius to orbit period, orbit decay, etc. 1L20.18 Orbits in a Spherical Cavity Derivation of the period of a ball orbiting in a spherical cavity. Strobe lights help this demo. 1L20.20 This demonstration consists of a 56 inch diameter hyperbolic funnel. Coins dropped into this funnel loosely approximate the behavior of matter spiraling into a gravity well. The orbits the coins make can be compared to planetary motion. 1L20.30 Rotating Gravitational Well A ball placed in a rotating potential well demonstrates the path of a satellite. Use a variable speed motor to show escape velocity. 1L20.35 Spin-Orbit Coupling Start a ball spinning like a top in a watch glass. It will convert the energy of its spin into an orbit. As time passes it converts more spin energy into larger orbits. See TPT 16(5), 316. 1L20.36 "Motion of Attracting Bodies" film A 7min computer animated film that covers Newton's laws, earth's gravity variations, satellite and binary orbits. 1L20.40 Conic Sections A dissectible cone, cut several ways can produce a circle, ellipse, parabola, and hyperbola. 1L20.45 Ellipse_Board The two pegs and string method for ellipse drawing on a whiteboard. 1L20.66 Gravity Represented by a Magnetic Field Drop a ball near a magnetron magnet and watch it complete less than one orbit. 1L20.71 "Planetary Motion and Kepler's Laws" A 9min computer animated film shows orbits of the planets, covers Kepler's second and third laws. (Lost Item)

fw: Gravity (last edited 2018-07-18 17:01:30 by srnarf)