Simple Machines Demonstrations

See also: Motion

Simple machines are basic devices that make work easier by changing the size or direction of a force. This category introduces levers, pulleys, wheels and axles, inclined planes, wedges, and screws. Studying simple machines helps explain mechanical advantage and the ways humans have harnessed physical principles to achieve tasks.

Demonstration	Materials	Difficulty	Safety	Summary
Bicycle Wheel Gyroscope	★★★	★★☆	★☆☆	A spinning bicycle wheel acts as a gyroscope. When you try to tilt the spinning wheel, it resists the change, demonstrating angular momentum and conservation of angular momentum.
Stirling Engine	★★★	★★☆	★☆☆	A low temperature Stirling engine placed over a cup of hot water runs as heat flows from the water to the engine, demonstrating energy conversion from heat to mechanical motion.
Disc vs Ring Moment of Inertia	★★☆	★☆☆	★☆☆	A disc and a ring of equal mass and diameter are released down an inclined plane to compare their rolling speeds. The demonstration shows how mass distribution affects moment of inertia and influences rotational acceleration.
Pascal’s Principle With Syringes	★★☆	★★☆	★★☆	Using syringes connected with tubing, students can demonstrate Pascal’s Principle: when pressure is applied to a confined fluid, the pressure increase is transmitted equally throughout the fluid. This allows a small force applied on a small piston to generate a larger force on a larger piston.
Simple and Compound Pulleys	★★☆	★★☆	★☆☆	This demonstration shows the difference between type 1 (fixed), type 2 (movable), and type 3 (compound) pulleys. Using low-friction pulleys, string, and measured masses, students observe how pulleys can reduce the input force required to lift weights and compare the forces using a force sensor.
Bicycle Gears	★☆☆	★☆☆	★☆☆	Bicycle gears are an application of the wheel and axle combined with levers. Changing gears adjusts the mechanical advantage, making pedaling easier for uphill climbs or faster for flat ground. The gear system demonstrates how force and distance trade off to achieve different outcomes.
Block and Tackle with Broomsticks	★☆☆	★☆☆	★☆☆	This demonstration uses two broom handles and a long rope to model a block and tackle pulley system. It shows how increasing the number of rope loops reduces the effort needed to pull two volunteers together, demonstrating mechanical advantage.
Door Knobs and Handles	★☆☆	★☆☆	★☆☆	A classroom door knob or handle demonstrates the lever principle. When force is applied to the handle or knob, it rotates the central spindle (fulcrum), which retracts the latch (load), allowing the door to open with minimal effort.
Friction of a Block on an Inclined Plane	★☆☆	★☆☆	★☆☆	A block is placed on a flat board that can be tilted to form an inclined plane. As the incline is raised, the block remains at rest until the downhill pull of gravity overcomes static friction, at which point it begins to slide. The angle at which sliding begins can be used to measure the coefficient of static friction, while constant-speed sliding demonstrates kinetic friction.
Gear Ratios	★☆☆	★☆☆	★☆☆	Gears are wheels with teeth that fit together to transfer motion, change speed, or change direction. By connecting large and small gears, you can build a gear train to explore how gears make work easier.
Third Class Levers in the Human Arm	★☆☆	★☆☆	★☆☆	This activity demonstrates how the human forearm works as a third-class lever. Students test lifting a bucket of sand with their arm and then create a cardboard model to visualize how muscles act as input forces.
Inclined Plane Spring Scale	★☆☆	★☆☆	★☆☆	Use a spring scale to compare the effort required to lift a 1000g mass straight up versus pulling it along an inclined plane at different angles. Students observe that a gentler slope reduces the required force, illustrating mechanical advantage and the tradeoff between force and distance.
Levers in Action	★☆☆	★☆☆	★☆☆	Students explore how different types of levers work by using everyday objects such as scissors, tweezers, a nutcracker, a stapler, and a teaspoon. They identify the positions of load, effort, and fulcrum, and classify the levers as first, second, or third class, depending on their setup.
Screws - A Ramp Around a Rod	★☆☆	★☆☆	★☆☆	A screw is a simple machine made by wrapping an inclined plane (a ramp) around a central rod. This design allows a small force applied over a long distance to be converted into a larger force, which can hold objects together or lift them. Everyday examples include screws, bolts, jar lids, and spiral staircases.
Second Class Levers	★☆☆	★☆☆	★☆☆	Students use a ruler, a stack of books, and a finger fulcrum to model a class two lever. By placing a load at different points on the lever, they observe how load position affects the effort required to lift it.
Seesaw Scales	★☆☆	★☆☆	★☆☆	Students build a simple seesaw model to explore how levers work. By balancing weights at different distances from a pivot, they learn how effort and load relate through the principle of leverage.
Simple Machines in a Zipper	★☆☆	★☆☆	★☆☆	A zipper demonstrates several simple machines working together. The zipper teeth act as wedges (inclined planes), while the zipper pull functions as a lever. The interlocking action of the wedges secures the zipper closed, and the lever provides the force to open or close it.
Simple Pully System	★☆☆	★★☆	★☆☆	This demonstration shows how to build a simple pulley using a spool, cardboard, and string to lift small objects. It introduces the concept of mechanical advantage and how pulleys reduce effort or change the direction of force.
Wedges	★☆☆	★☆☆	★☆☆	A variety of ways to demonstrate the wedge, including hammering nails, using an axe and dragging different shaped blocks through rice

Materials
★☆☆ Easy to get from supermarket or hardware store
★★☆ Available in most school laboratories or specialist stores
★★★ Requires materials not commonly found in school laboratories

Difficulty
★☆☆ Can be easily done by most teenagers
★★☆ Available in most school laboratories or specialist stores
★★★ Requires a more experienced teacher

Safety
★☆☆ Minimal safety procedures required
★★☆ Some safety precautions required to perform safely
★★★ Only to be attempted with adequate safety procedures and trained staff