Conservation of Energy Concept

Demonstrations in Conservation of Energy

Black bowling ball suspended by a thin green cable with carabiner, hanging at seat height next to a gray metal stool in a lecture hall
Safety

Bowling Ball Pendulum

A bowling ball pendulum released from a volunteer's chin swings away and returns to exactly its release height, dramatically demonstrating conservation of mechanical energy. The volunteer's safety depends entirely on …
Loop track apparatus: metal channel track in a rectangular frame, with a long ramp descending from the left into a circular loop, then a short exit ramp on the right

Loop Track

Demonstrates conservation of mechanical energy using a loop track. A ball released from a given height cannot exceed that height on the opposite side. By varying release height, students see …
Double-incline track: two metal rails pivoting at center, with wooden blocks propping up each end to adjustable heights, on a demonstration table in front of a chalkboard

Double-Incline Track

A ball released from a given height on one side of a V-shaped track rises to approximately the same height on the other side, regardless of the slope angle. Demonstrates …
Red flexible track mounted on a blackboard with magnetic clips, shaped in a wavy path with two dips, elevated at the left end and lower at the right
Safety

Flextrack

Demonstrates that a ball bearing's final kinetic energy depends only on its change in height, not the path taken. Students see that different track configurations with the same start and …
Ballistic pendulum frame on a wooden base: cylindrical pendulum block suspended by strings from an aluminum vertical rail, with a golf pencil as the altitude indicator and graph paper clipped to an acrylic shield at right
Safety

Compressed Air Ballistic Pendulum

Demonstrates the ballistic pendulum: a compressed-air gun fires a steel ball into a pendulum, combining conservation of momentum (inelastic collision) and conservation of energy (pendulum swing) to determine projectile velocity …
Ballistic pendulum apparatus: a tall floor-standing tripod base supports long metal rods converging at the top, with a pendulum bob and target suspended at center. A curved metal scale sits at the base for measuring the ball's release position.

Ballistic Pendulum

A swinging ball strikes and sticks to a target in a perfectly inelastic collision. Students apply momentum conservation (collision) and energy conservation (pendulum swing) sequentially to determine the ball's initial …
Light blue PVC cannon tube standing upright on a wooden base with a small ignition hole near the bottom, basketball sitting alongside on the lecture hall floor
Safety

Basketball Cannon

Ethanol vapor combustion inside a PVC cannon launches a basketball, dramatically demonstrating chemical-to-kinetic energy conversion. Students trace the energy transformation chain and discover that only a tiny fraction of the …
Spring-loaded tennis ball launcher: large clear acrylic tube with coiled spring inside, mounted on a metal base plate with clamp, plunger rod standing alongside, and tennis ball resting next to the base
Safety

Spring-Launched Tennis Ball

A compressed spring launches a tennis ball vertically, converting elastic potential energy to kinetic and gravitational potential energy. Varying the compression distance shows the quadratic relationship.
Four jumping toys on a clear acrylic sheet: a small green witch figure with black base (top left), two teal grasshoppers with wire legs, and a green rubber hemisphere with a flame-decorated knob on top (bottom right)

Jumping Toys

A collection of toys that store elastic potential energy through different mechanisms (suction cups, springs, inverted rubber) and release it as kinetic energy. Useful in any discussion of stored energy …
Two rattlebacks on a gray surface: a black elongated boat-shaped rattleback (left) and a shorter red oval rattleback with an adjustable black vane secured by a silver screw (right)

Rattleback

A rattleback is an asymmetric spinning object with a preferred spin direction. When spun the "wrong" way, it rocks violently and reverses direction. Demonstrates coupling between rotational modes and the …