Motion Demonstrations

See also: Force, Simple Machines

Motion describes how objects change their position over time. This category introduces concepts such as speed, velocity, and acceleration, along with the relationships between force and motion. Studying motion provides a framework for predicting and explaining how objects behave in both everyday and scientific contexts.

Demonstration	Materials	Difficulty	Safety	Summary
Two Falling Coins - Projectile Motion	★☆☆	★☆☆	★☆☆	Two coins are released from the same height: one falls straight down while the other is given a horizontal push. Both hit the ground simultaneously, demonstrating that horizontal velocity does not affect vertical motion.
The Tablecloth Trick	★☆☆	★★☆	★★☆	A tablecloth is pulled quickly from under cups and plates, leaving them in place.
The Spinning Can	★☆☆	★★☆	★☆☆	A can with small angled holes near its base will spin when filled with water and suspended.
Surface Friction	★★☆	★☆☆	★☆☆	Students drag a wooden block over different surfaces using a spring scale, recording the steady pulling force to compare kinetic friction. Results are analyzed across at least three trials per surface and used to discuss variables, error sources, and friction concepts.
Stomp Rocket	★☆☆	★★☆	★★☆	Students build and launch paper rockets using a plastic bottle, garden hose, and card. By stomping on the bottle, compressed air is forced through the hose, propelling the rocket upwards in a demonstration of Newton’s Third Law.
Stacked Ball Drop	★☆☆	★☆☆	★☆☆	A ping pong ball is dropped alone, with a golf ball, and then stacked above the golf ball to observe differences in rebound height. The demonstration shows how energy conservation and transfer limit the maximum possible bounce height.
Simple Electric Motor	★★☆	★★☆	★☆☆	A simple electric motor is built using a coil of wire, a battery, paperclips, and strong magnets. The motor works by converting electrical energy into mechanical motion through the interaction of a magnetic field from a permanent magnet and a temporary magnetic field created by current flowing in the coil.
Simple Accelerometer	★☆☆	★☆☆	★☆☆	This demonstration uses a cork suspended in water inside a jar to show how acceleration affects fluids and objects. Instead of moving opposite to acceleration as many students expect, the cork moves in the same direction as acceleration because of pressure differences in the water.
Shoot the Monkey	★★★	★★☆	★★☆	This classic demonstration shows that the horizontal and vertical components of a projectile’s motion are independent. A projectile fired from a cannon hits a monkey that drops from a tree at the same instant, because both fall with the same vertical acceleration due to gravity.
Shaken Soda Can Race	★☆☆	★☆☆	★☆☆	When two identical soda cans roll down an incline, the unshaken can reaches the bottom first. Shaking one can creates foam and bubbles that change the distribution of mass inside, altering its moment of inertia and causing more energy transfer to the fluid. This reduces the shaken can’s rolling speed.
Rotating Chair with Dumbbells	★★☆	★☆☆	★★☆	A person seated on a rotating chair holds dumbbells with arms extended. As the person pulls the dumbbells inward, the chair spins faster, demonstrating conservation of angular momentum. Extending the arms again slows the rotation.
Rollback Can	★☆☆	★☆☆	★☆☆	A weighted rubber band is suspended inside a can. Rolling the can forward twists the band and stores elastic potential energy; when the can stops, the band unwinds and drives the can to roll back.
Projectile Motion Range	★★☆	★☆☆	★★☆	Students determine the muzzle velocity of a spring launcher from a horizontal shot, then use kinematics to predict and test the range of a projectile launched at selected angles over level and uneven terrain. The activity connects measured distances and heights to time of flight and horizontal range using constant-acceleration equations.
Potato Inertia	★☆☆	★☆☆	★☆☆	This demonstration shows how inertia works by striking a knife that has been inserted into a potato. The potato resists sudden motion, so the knife moves deeper into it, illustrating Newton’s First Law of Motion.
Ping Pong Vacuum Cannon	★★★	★★★	★★★	A sealed tube is evacuated and a ping pong ball is placed near one end. When the near seal is ruptured, atmospheric pressure accelerates the ball down the evacuated tube with negligible air resistance, allowing extreme speeds that can puncture cans and thin plywood. This demonstration highlights gas pressure, Newton’s laws, and the role of drag.
Pendulum Period Investigation	★☆☆	★☆☆	★☆☆	Students build a simple pendulum and test how string length, bob mass, and release angle affect the time for one swing. The demonstration shows that for small angles the period depends mainly on length, not mass or amplitude.
Newton's Cradle	★★☆	★☆☆	★☆☆	A Newton’s cradle demonstrates conservation of momentum and energy through swinging metal spheres that collide in sequence. When one or more spheres are released, the same number of spheres on the opposite side swing out with nearly identical motion.
Natural Selection with Paper Airplanes	★☆☆	★☆☆	★☆☆	Students model directed evolution by making and testing paper airplanes. The best flyers are selected each round, and their designs are modified and re-tested. Over time, the average flight distance improves, simulating natural selection and directed evolution.
Jumping Coin with Bernoulli’s Principle	★☆☆	★★☆	★☆☆	This demonstration shows how a coin can appear to jump into a cup under its own power. By blowing in a specific way, air pressure differences created by the Bernoulli principle cause the coin to lift and move into the cup.
Inertia Hat	★☆☆	★★☆	★☆☆	A wire coat hanger is shaped into a headpiece holding two tennis balls. When balanced on the head, the ball remain still when the person turns.
Inertia - Which String Breaks	★★☆	★☆☆	★☆☆	A heavy mass suspended by a top string has a string hanging from the bottom. A quick pull on the lower string causes it to snap due to the ball’s inertia, while a slow pull causes the top string to break because it the gravity of the mass add to the force.
Happy and Sad Balls	★★★	★☆☆	★☆☆	This demonstration compares how different materials affect energy transfer in collisions. A "happy" ball made of neoprene rubber bounces high, showing an elastic collision, while a "sad" ball made of norbornene barely bounces, showing an inelastic collision.
Gravity Visualized	★☆☆	★★☆	★☆☆	Stretching fabric over a frame to create a “spacetime” surface lets students see how mass curves space and guides motion. By placing heavy and light objects on the fabric and rolling marbles, the class can model orbits, accretion, tides, and even visualize gravitational waves.
Force Table Vector Addition	★★★	★★☆	★☆☆	Using a force table with pulleys and hanging masses, students create one or more known forces on a central ring and determine the equilibrant that brings the system to equilibrium.
Floating Ping Pong Ball	★☆☆	★☆☆	★☆☆	A ping pong ball can be suspended in the air stream of a hair dryer. This demonstrates Bernoulli’s principle, which explains how differences in air pressure keep the ball floating and stable in the moving air.
Egg Drop Inertia	★☆☆	★★☆	★★☆	An egg is balanced on a cardboard tube above a glass of water, with a pie pan in between. By quickly knocking the pan away, the tube and pan move aside, but the egg drops straight down into the glass of water, demonstrating Newton’s First Law of Motion.
Dropping Coin and Feather in a Vacuum	★★★	★★☆	★★☆	This demonstration shows that in the absence of air resistance, all objects fall at the same rate. A coin and a feather dropped in a tube filled with air fall at different speeds, but when the tube is evacuated, they fall together.
Dropping Balls From Same Height	★☆☆	★☆☆	★☆☆	This demonstration shows that all objects fall at the same rate under gravity regardless of their mass. Two balls of different sizes dropped at the same time hit the floor together. When one ball is dropped vertically and the other is tossed horizontally from the same height, they still land at the same time.
Dollar Bill Inertia Challenge	★☆☆	★☆☆	★★☆	This demonstration uses a dollar bill, coins, and soda bottles to show Newton’s First Law of Motion. When the bill is quickly pulled away, the coins or bottle remain in place due to inertia, as long as friction is minimized.
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.
Centripetal Force with Bucket	★☆☆	★☆☆	★☆☆	A bucket of water is swung in a vertical circle without the water spilling out. This demonstrates inertia and the role of centripetal force in circular motion.
Center of Gravity	★☆☆	★☆☆	★☆☆	This demonstration shows how to find the center of gravity of an irregular object by hanging it from different points and drawing plumb lines. It also illustrates that the center of gravity moves in a simpler path than other points when the object is spun.
Catch a Falling Dollar	★☆☆	★☆☆	★☆☆	This experiment demonstrates human reaction time using a dollar bill. A person tries to catch the bill as it falls, but usually fails because the human reaction time is slower than the time it takes the bill to drop through their fingers.
Bottle Rocket	★★☆	★★☆	★★☆	A plastic soda bottle partially filled with water is pressurized with air using a pump. When released, the escaping air and water propel the bottle upward, demonstrating Newton’s Third Law of Motion and the relationship between force and acceleration.
Balloon Rocket	★☆☆	★☆☆	★☆☆	A balloon taped to a straw travels along a taut string when released, demonstrating Newton’s Third Law of Motion: the escaping air (action) pushes the balloon forward (reaction). The setup provides a simple model of rocket propulsion.
Balloon Hovercraft	★☆☆	★☆☆	★☆☆	A CD, balloon, and sport drink cap are assembled into a simple hovercraft that demonstrates Newton’s Third Law of Motion and the reduction of friction. Air from the balloon escapes downward through the CD hole, lifting and moving the hovercraft.
Ballistic Car	★★★	★★☆	★☆☆	The Ballistic Car shows that horizontal motion is unaffected by vertical forces. A spring launcher on a moving cart shoots a ball straight upward; the ball then falls back into the barrel, proving that both cart and ball share the same horizontal velocity.
Air Track Demonstrations	★★★	★★☆	★☆☆	Use a low-friction air track and gliders to demonstrate core kinematics and dynamics ideas including uniform motion, acceleration, momentum, and collisions.

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