Cavendish Experiment
Description: Henry Cavendish was the first scientist to measure the gravitational force between two objects in the laboratory using a gravitational torsion balance. In this video physics teacher Andrew Bennett attempts to recreate this experiment. Reading the comments section is very interesting. Pseudoscientific flat-earthers attempt to point out errors in the Mr. Bennett's experiment. Students could attempt to recreate the experiment or join in the conversation.
Web Resources: Cavendish Experiment - Wikipedia, Gravitational Torsion Balance - Pasco
Flymo Hover Lawnmower
Description: The Flymo hover mower is built on the same principles as a hovercraft. It contains a fan above the cutting blade that generates lift. This could be used as a phenomenon to explore balanced forces and gravity.
Web Resources: Flymo Hover Mowers, Flymo - Wikipedia
Raw or Boiled Egg Experiment
Description: This is a simple experiment to demonstrate the idea of inertia. Students could be given eggs that are both raw and boiled and they could use evidence to support the identity of the labeled eggs. In the raw egg the yolk and fluid act as independent objects and so they will continue moving when the egg is briefly stopped.
Web Resource: Newton’s First Law - the Physics Classroom
A Bed of Nails
Description: Special caution should be taken when sitting down or getting up from a bed of nails. In this video, Steve Spangler used a motor to lift the entire bed of nails up and down safely. Each of the nails is pushing on the participant but since there are so many nails the force is distributed safely between all of the nails. This demonstration could be used in any physics unit discussing forces and pressure.
Web Resource: Bed of Nails - Wikipedia
Amazing Rube Goldberg Machines
Description: Rube Goldberg machines are named after American cartoonist Rube Goldberg who drew complicated steps involved in doing a fairly simple task (like pouring milk in a glass). Students can study these machines, or build their own, to show how energy can be converted through a series of interactions. In lower elementary classes they might be shown or built to show how pushes or pulls can change the motion of objects. As they move through school they should start to identify specific collisions, interactions, and conversions of energy.
Web Resources: Rube Goldberg Machines - Wikipedia
Weighing the World
Description: The Schiehallion experiment was an attempt to measure the mass of the earth using a pendulum and a mountain (Mount Schiehallion). The mass of the mountain was approximated and the deflection of a pendulum due to the gravitational force of the mountain was measured. Students could attempt to do the calculations or even repeat the experiment on a nearby mountain.
Web Resource: Schiehallion Experiment - Wikipedia
Slow Motion Golf Ball Collision
Description: In this dramatic slow motion video a golf ball collides with a piece of steel showing a large amount of compression. Different golf balls are designed to have varying amounts of compression based on the desired behavior of the ball. In a kindergarten class golf balls or baseballs are great examples of pushes causing changes in the motion of an object. In the upper grades this could be a great example of a collision. Students could investigate the behavior of different golf balls (or clubs) and even do some designing themselves.
Web Resource: Golf Ball - Wikipedia
Amazing Slinky Tricks
Description: The Slinky was invented by Richard James, an engineer, who was working with springs to support and stabilize equipment on a ship. Simple slinky tricks show how forces (pushes and pulls) change the direction of an object. Students can design a set of stairs, or obstacles, that the Slinky can navigate. In the secondary science classroom it can be used to investigate inertia, oscillations, and Hooke's law. This phenomenon can also be used to investigate wave properties.
Web Resource: Slinky - Wikipedia
Magnetic Cannon
Description: The magnetic cannon contains four spaced neodymium magnets in a channel. Two balls bearings are placed between each ball bearing. When a new ball bearing is introduced a transfer of energy occurs and the final ball bearing leaves with a higher initial velocity than the first. This is a great phenomenon for studying transfer of momentum and the energy of an object based on its position within a magnetic field.
Web Resource: Magnetic Challenge with Bozeman Science
