Free online science and maths tools

Plots the reaction force at the pivot of a swinging pendulum.

Drops blocks into a pile and watches the rigid body stacking.

Collides polygon shapes with each other in a 2D physics engine.

Simulates colliding rigid bodies with adjustable elasticity.

Applies forces to a rigid body and shows resulting motion and rotation.

Simulates a double pendulum made of two rigid rods and its chaotic motion.

Simulates a car on an editable roller coaster track with energy graphs.

Roller coaster car that can leave the track and fly as a projectile.

Roller coaster car attached to a spring while rolling on a track.

Simulates a simple pendulum with graphs of angle, velocity and energy.

Models three atoms joined by springs to show vibration modes.

Solves the wave equation on a string and shows how it vibrates.

Tests strong and weak acids and bases to see ion counts, pH and conductivity.

Practice balancing equations by adjusting coefficients with a visual atom count.

Shines light through colored solutions to relate concentration, path length and absorbance.

Shows refraction and reflection of light between media and with prisms and lenses.

Adjusts temperature to show how blackbody spectrum and peak wavelength shift.

Assembles molecules from atoms to meet collection targets and view 3D structure.

Add protons, neutrons and electrons to a model atom and watch which element, charge and mass result.

Lets you assemble batteries, bulbs, resistors and switches into DC circuits and read meters.

Collides balls in one or two dimensions and checks momentum and energy conservation.

Mixes colored light to show how the eye perceives color.

Compares masses and volumes of blocks in water to explore how density affects floating.

Tracks energy as it moves between heating, light and motion in a set of linked systems.