The Scientist Lounge

Projectile Motion

Launch an object and watch it fly; adjust speed and angle to explore range and height.

Vertical Drop

Drop an object and see how height, air resistance, and mass affect the fall.

Elastic Collision

Two balls collide on a frictionless track; watch momentum and kinetic energy stay perfectly conserved through every bounce.

Curved Ramp

A frictionless ball slides down a curved ramp; change the shape to see the descent time change while the bottom speed stays the same.

Simple Pendulum

A pendulum swinging under gravity with adjustable length and initial angle.

Circular Motion

An object moving in a circle showing centripetal force and velocity vectors; adjust radius, speed, and mass to explore the relationships.

Spring-Mass System

A mass on a spring demonstrating Hooke's law and undamped simple harmonic motion; adjust spring constant, mass, initial velocity, and amplitude to explore conservation of energy.

Inelastic Collision

Two objects collide and stick together; watch momentum stay conserved while kinetic energy is lost to deformation.

Orbital Motion

A planet orbiting a star showing gravitational force and orbital velocity; adjust orbit radius and star mass to explore Kepler's laws.

Rolling Disk

A disk rolling down an incline showing rotational and translational motion; adjust the angle and radius to explore the rolling constraint.

Friction and Forces

A ramped push builds until it defeats static friction, releases the block at 8 m/s, and kinetic friction slides it to rest; adjustable static and kinetic coefficients set the breakaway and the stopping distance.

Atwood Machine

Two masses connected by a string over a pulley demonstrating Newton's second law; adjust the masses to see how the weight difference drives acceleration.

Projectile with Drag

A projectile launched with adjustable air resistance showing the effect of drag on trajectory.

Full Projectile Sandbox

The capstone projectile sandbox: gravity, drag relative to moving air, and Magnus spin lift all at once. Every earlier sim in the family is this model with one or more knobs turned off.

Magnus Effect

Spin bends a projectile's flight: back-spin lifts the ball so it carries farther on a flatter line and the best launch angle drops well below 45°, while top-spin makes it dive.

Projectile in Wind

Launch a projectile through moving air and watch quadratic drag act on its speed relative to the wind: a head-wind shortens the range, a tail-wind extends it, and with drag off the wind stops mattering.

Inclined Plane

An object sliding down an adjustable incline with friction and normal force vectors.

Double Pendulum

Two connected pendulums exhibiting chaotic motion under gravity: tiny differences in starting angles produce wildly different paths.

Escape Velocity

A projectile launched from a planet surface showing the threshold speed to escape gravity.

Torque & Lever

A lever with movable masses demonstrating torque balance and rotational equilibrium.

Damped Spring

A spring-mass system with adjustable damping showing underdamped, critical, and overdamped motion.

Bounce on Grass vs. Turf

Drop a ball, watch it bounce and roll; pick grass, turf, or wet grass and see how the surface alone changes the outcome.

Corner Kick into the Box

Top-down corner kick with Magnus curl, drag, and wind. Land the ball in a target zone at the far post.

Magnus Effect Free Kick

Curl a free kick around a wall: Magnus force perpendicular to velocity, plus quadratic drag. Top-down half-pitch with goal at 30 m.

Penalty Kick: Speed vs. Keeper Reaction

An 11-metre shot becomes a race of two clocks: ball travel time vs goalkeeper reaction plus dive. Tune both sides and see when each wins.

Foot–Ball Collision

Watch the foot strike the ball: a closed-form impulse model from foot mass, foot speed, and the coefficient of restitution.

2D Collision

Two objects colliding at angles in two dimensions with adjustable masses and velocities.

1D Motion Plotter

An object moves along a line; set initial position and velocity with sliders and watch a live position-vs-time graph trace the result.

Two Runners Position

Two runners with adjustable starting points and constant speeds; the simulation stops when the first runner crosses the 100 m finish line.

Velocity-Time Plotter

A cart with adjustable constant acceleration; a dual-axis chart plots velocity (left axis, blue) and position (right axis, green) against time, with the shaded triangle showing that area-under-v equals displacement.

Average vs Instantaneous Velocity

A position-time curve with a draggable secant line that shrinks to a tangent, illustrating the limit definition of instantaneous velocity.

Constant Acceleration Cart

A cart with constant acceleration; live position, velocity, and acceleration plots update side by side

Variable Acceleration

Adjust a peak-acceleration slider to shape a piecewise-linear acceleration-time profile; the simulation integrates it in real time to reveal velocity and position, the graphical meaning of kinematic integration.

Feather and Hammer

A feather and hammer dropped together with adjustable air density, from perfect vacuum to full atmosphere.

Free Fall on Different Planets

Drop an object on Earth, Moon, Mars, or Jupiter with adjustable g and matching fall times

Projectile on an Incline

Launch a projectile up an adjustable slope and discover the angle that maximises range: the optimum generalises to θ = 45° + φ/2.

Projectile from a Cliff

Projectile launched from elevated platform with adjustable height, angle, and speed; trajectory and impact point shown

Catch the Falling Cat

A firefighter's net-launcher aims dead-on at a cat perched on a ledge that drops the instant the net fires; both fall together under gravity, so a direct aim always catches the cat.

Circular Motion Vectors

An object on a circular track with live position, velocity (tangent), and centripetal acceleration vectors.

Period vs Radius

Adjust the radius of a uniform circular orbit at fixed speed; period and frequency update live with the visualization.

Puck on Ice

A puck sliding on ice with a logarithmic friction slider spanning three decades (μk = 0.0001 to 0.1): from idealized frictionless through real hockey-puck-on-ice to rough/worn ice, watch inertia in action.

Newton's Third Law: Pushing Carts

Two carts pushed apart by an equal internal spring force: equal and opposite impulses leave total momentum at zero, while the lighter cart reaches proportionally greater speed.

Free-Body Diagram Builder

Place an object on an inclined surface with friction and an applied force; all force vectors render live with labeled magnitudes.

Coulomb's Law

Two point charges with adjustable signs and magnitudes: the electrostatic force vector follows F = kq₁q₂/r² and flips direction when charge signs differ.

Friction on an Incline

A block on an inclined plane: adjust the angle and friction coefficients to find the exact angle at which slipping begins.

Two-Rope Tension

A load hangs from two ropes at adjustable angles; each rope's tension is shown as a labelled vector and a force triangle that closes at equilibrium.

Connected Carts on a Rope

Two carts connected by a rope, with one pulled by an external force; tension is identical throughout

Elevator Apparent Weight

A person on a scale inside an accelerating elevator; the scale reading changes with elevator acceleration

Normal Force on an Incline

Block on an incline with adjustable angle; normal force decreases as cosine of the angle

Terminal Velocity

An object falling through fluid with quadratic drag reaches terminal velocity that depends on mass and cross-section.

Conical Pendulum

A ball on a string traces a horizontal circle; tension and centripetal force decompose with adjustable string angle

Pendulum Energy Bars

A swinging pendulum with KE and PE bars exchanging; total energy stays flat without friction, decays with damping

Kinetic Energy vs Velocity

An object with adjustable mass and speed; KE bar grows quadratically with velocity, linearly with mass

Launcher on a Platform

A cart rolls at constant speed and fires a ball straight up; the ball inherits the cart's horizontal velocity and lands right back in the moving cart.

Cannon on a Moving Cart

A cannon rides a cart rolling at constant speed and fires a shell at an angle; the shell inherits the cart's horizontal velocity, so its ground-frame path differs from the symmetric arc seen in the cart's own frame.

Banked Curve

A car on a banked curve at adjustable angle and friction; find the ideal speed where no friction is needed.

Gas in a Piston

Drag a piston to compress or expand a gas at fixed temperature; the pressure readout rises as volume falls (PV = nRT) while a live point traces the P–V curve in a side panel

Falling Sphere Viscometer

A small dense sphere settles slowly through a viscous liquid (glycerin) in the laminar, low-Reynolds regime where Stokes drag, linear in speed and proportional to viscosity, balances buoyancy-corrected weight. Terminal settling speed scales inversely with viscosity, the controlling slider.

Wave Speed on a String

Adjust string tension and linear density; pulse speed varies as √(T/μ)

Snell's Law

A ray crossing between two media with adjustable indices; bend angle follows n₁sinθ₁ = n₂sinθ₂

Mirror Reflection

A flat mirror and a draggable incident ray; reflected ray always matches angle of incidence

Work by a Variable Force

Drag a force-vs-position curve; the area under it computes total work and matches the kinetic energy gained

Net Work with Friction

A block pushed across a surface with friction; work done by each force tabulated and summed to net work = ΔKE.

Gravitational PE on a Hill

Drag a ball up and down a curved hill; the PE bar reads from the chosen reference height, showing that gravitational potential energy is always relative.

Spring Potential Energy

Compress or stretch a spring; PE rises quadratically with displacement, with U-vs-x graph alongside

Roller Coaster

A cart on a track with hills and a loop; live KE, PE, and total-energy bars show energy conservation throughout the run.