Table of Mechanics Mechanics (1Q): Rotational Dynamics Lecture Demonstrations

## Properties of Matter

PIRA classification 1R

62 Demonstrations listed of which 26 are grayed out

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

# 1R10. Hooke's Law

 PIRA # Demonstration Name Abstract 1R10.10 Hooke's_law (The Big Spring) Add weights to a large vertical spring one kg at a time. Examining the force-displacement which is marked in Newtons. 1R10.25 Pull on a Horizontal Spring Pull on a horizontal spring with a spring scale. 1R10.30 Springs in Series and Parallel Pull on a spring, springs in series, and springs in parallel with a spring scale. Compare the force required to stretch each case.

# 1R20. Tensile and Compressive Stress

 PIRA # Demonstration Name Abstract 1R20.10 Breaking Wire Add weights to wire that is attached to the ceiling until the wire breaks. Insert a large spring scale if one wishes. 1R20.11 Elastic Limits Stretch springs of copper and brass. The copper spring remains extended. 1R20.15 Young's Modulus Hang weights from a wire that runs the length of the benches. Add 1/2 kg masses to the copper wire and show that the Stretched deflection goes back when the mass is removed. Use either laser and mirror optical lever to display the deflection or a arrow on the pulley. Add a lot of mass to show the Elastic Limit. 1R20.18 Poisson's Ratio A rubber hose is stretched to show lateral contraction with increasing length. 1R20.20 Bending or Sagging Board Ten lbs. is hung from the center of a meter stick supported at the ends. Orient the meter stick on edge and then on the flat. Place the ends of a thin board on blocks, then add mass to the center. 1R20.20 Beams Under Stress A rectangular cross section bar is loaded in the middle while resting on narrow and broad faces. Hang weights at the ends of extended beams. Use beams of different lengths and cross sections. Hang weights at the ends of extended beams. Use beams of different lengths and cross sections. 1R20.27 Aluminum/Steel Elasticity Paradox Copper and brass rods sag different amounts under their own weight but steel and aluminum do not. 1R20.31 Stretch a Hole Holes arranged circle in a rubber sheet deform into an ellipse when stretched. 1R20.32 Deformation Under Stress A pattern is painted on a sheet of rubber and deformed by pulling on opposite sides. 1R20.38 Stress on a Brass Ring A strain gauge bridge is used to measure the forces required to deform a brass ring. Diagram. Construction details. 1R20.60 Bologna Bottle Pound a nail with a Bologna bottle, then add a carborundum crystal to shatter the bottle. 1R20.70 Prince Rupert's Drops Drops of glass cooled quickly can be hit with a hammer but shatter when the tip is broken off.

# 1R30. Transfer of Angular Momentum

 PIRA # Demonstration Name Abstract 1R30.10 Shear Pages of a Book Use a very thick book to demonstrate shear. 1R30.11 Shear_Cards Use a tall stack of cards placed sequentially off-center to create a ledge. 1R30.20 Materiel Shearing Push on the top of a large foam block or use a large sponge or use a rectangular block of rubber to show shear of different materials. 1R30.30 Spring Cube A 3x3x3 cube of 27 cork balls is held together with springs. 1R30.31 Plywood Sheets A stack of plywood sheets with springs at the corners is used to show shear, torsion, bending, etc. 1R30.35 Shear and Stress Modulus Unsophisticated apparatus for measuring elastic constants of a thin flexible strip and rod. 1R30.40 Torsion Rod Rods of various materials and diameters are twisted in a torsion lathe. 1R30.41 Bending and Twisting Wind a copper strip around a rod and then remove the rod and pull the strip straight to show twisting. 1R30.45 Shear and Twist in Screw Dislocation Rule a thick walled vacuum tube with a grid, slit lengthwise, and dislocate one unit. 1R30.xx Train on a Bicycle Wheel An "O"- Scale train is placed on a horizontal bicycle wheel that is free to rotate. When the train is running, one can let the train go around the track or have it stand still will the track is rotating underneath. 1R30.xx Wheel and Axle I A large mid-evil looking wheel on an axle. A large lead ball on a rope is wound up on the axle and the wheel free to rotate.

# 1R40. Coefficient of Restitution

 PIRA # Demonstration Name Abstract 1R40.10 Bouncing Ball Drop balls of different material on to a tool steel plate. Loss of mechanical energy in the coefficient of restitution. Drop balls on a glass plate. Balls of various materials are bounced off plates of various materials. 1R40.12 Coefficient of Restitution Rubber balls of differing elasticity and silly putty are dropped in a clear tube near a meter stick onto a steel surface. 1R40.13 Coefficient of Restitution in Baseballs Analysis leading to a prediction of up to 15 foot difference in long fly balls due to variation in coefficient of restitution. 1R40.30 Happy and Sad Balls A bouncy ball and a non-bouncy ball are dropped from the same height with very different outcomes demonstrating the difference between elastic and inelastic collisions.

# 1R50. Crystal Structure

 PIRA # Demonstration Name Abstract 1R50.10 Solid Shapes How to make solid tetrahedrons and octahedrons. How to make Solids 1R50.15 Solid Models Styrofoam balls and steel ball bearings are used to make crystal models. 1R50.16a Lattice Models Show model of Body Centered Cubic (BCC) 1R50.16b Lattice Models Show model of Face Centered Cubic (FCC) 1R50.16c Lattice Models Show model of Hexagonal Close Packed (HCP) 1R50.16d Lattice Models Show model of Miller Indices 1R50.16e Lattice Models Show model of Sphalerite Model 1R50.16f Lattice Models Show model of Wurtzite Model 1R50.18 Elastic Crystal Models Crystal models are built with a combination of compression and tension springs. 1R50.20a Crystal Lattice Models Show model of Calcite 1R50.20b Crystal Lattice Models Show model of Calcite 2 1R50.20c Crystal Lattice Models Show model of Carbon Dioxide 1R50.20d Crystal Lattice Models Show model of Cesium Chloride 1R50.20e Crystal Lattice Models Show model of Copper 1R50.20f Crystal Lattice Models Show model of Diamond {MISSING} 1R50.20g Crystal Lattice Models Show model of Fluorite 1R50.20h Crystal Lattice Models Show model of Germanium 1R50.20i Crystal Lattice Models Show model of "N" Germanium 1R50.20j Crystal Lattice Models Show model of "P" Germanium 1R50.20k Crystal Lattice Models Show model of Graphite I 1R50.20l Crystal Lattice Models Show model of Graphite II 1R50.20m Crystal Lattice Models Show model of Magnesium 1R50.20n Crystal Lattice Models Show model of Silicone 1R50.20o Crystal Lattice Models Show model of Sodium Chloride 1R50.20p Crystal Lattice Models Show model of YiBCO 1R50.22 Tennis Ball Crystals Old tennis balls stacked together to give two close packed crystals. 1R50.30 Crystal Structure Show natural crystals of salt, quartz, and other minerals, and lantern slides of snow crystals. 1R50.31 Crystal Growth in a Film Crystal growth on a freezing soap film is observed through crossed Polaroids 1R50.31 Ice Nuclei Large ice crystals form on the surface of a supercooled saturated sugar solution. 1R50.32 Make Tin Crystal Pour pure tin into a Pyrex mold, other steps. 1R50.40 Stacking Fault Model A closest packing spheres model that demonstrates a fault going from fcc to hcp. 1R50.40 Crystal Faults One layer of small ball bearings between two Lucite sides. 1R50.45 Crushing Salt A large salt crystal is crushed in a "c" clamp.