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Physics Fundamentals

Gravity
Lab

Launch projectiles. Solve physics puzzles.
9 levels of real physics — no hand-holding.

Drag to aim • Release to fire • Press R to reset
🎮 Free Physics Game

Gravity Lab — The Free Online Physics Game That Makes You Think

Gravity Lab is a free physics game that teaches real projectile motion, gravity, and collision physics through hands-on puzzles — no textbooks, no lectures, just intuition built through play. Drag, aim, fire, and discover Newton's laws for yourself.

How to Play Gravity Lab

  1. 1
    Aim your launcher: Click and drag (or touch and drag on mobile) from anywhere on the screen. A dashed trajectory arc shows your predicted path in real time.
  2. 2
    Set your power: Drag further from your starting point to increase launch power. The percentage readout in the top-left shows how much power you're applying.
  3. 3
    Release to fire: Let go of the mouse or lift your finger. The ball launches with real projectile physics — gravity, air resistance, and elastic bounces all apply.
  4. 4
    Hit the targets: Each level has one or more glowing cyan targets. Hit them all within your shot limit to complete the level.
  5. 5
    Earn stars: Use fewer shots for higher star ratings. 3 stars = perfect. Every level can be replayed for a better score.
  6. 6
    Navigate obstacles: Later levels add walls, moving targets, gravity zones, and air resistance. Use the trajectory preview to plan your shot.

The Physics Behind the Game

Every element of Gravity Lab is grounded in real physics equations. The game is a physics simulator first and a game second — here's the science powering every shot.

Projectile Motion

The ball follows the classic kinematic equations derived by Galileo and formalised by Newton. Horizontal and vertical motion are completely independent.

x(t) = v₀·cosθ·t
y(t) = v₀·sinθ·t − ½·g·t²
Range R = v₀²·sin(2θ) / g

→ Covered in our article on Projectile Motion and Why Is Projectile Motion a Parabola?

Gravity & Free Fall

Earth's gravitational acceleration is 9.8 m/s² downward. In Gravity Lab's scaled simulation, gravity zones can multiply or reduce this value, showing how range changes dramatically with gravitational strength.

F = mg, a = g ≈ 9.8 m/s² (Earth)

→ See Free Fall and Terminal Velocity

Elastic Collisions & Coefficient of Restitution

When the ball bounces off floors and walls, the collision is partially elastic. The coefficient of restitution (e = 0.72) determines how much velocity is preserved after impact.

v′ = −e·v (e = 0.72)

Simple Harmonic Motion

Moving targets oscillate using SHM — the same equation that describes pendulums, springs, and atomic vibrations.

x(t) = A·cos(ωt + φ)

→ See Simple Harmonic Motion

Air Resistance (Drag Force)

Enabled in levels 7 and 9, air drag applies a force proportional to velocity squared, reducing range and shifting the optimal launch angle below 45°.

F_d = ½ρC_dAv²

→ See Terminal Velocity and Drag

What You'll Learn Playing Gravity Lab

Gravity Lab — Level Guide

Level 1
First Launch

A clear line to the target. Master the trajectory arc and learn how launch angle affects distance. Pure projectile motion.

Level 2
Over the Wall

A tall wall blocks the direct path. You must loft the ball over — demonstrating that vertical and horizontal motion are independent.

Level 3
Moving Target

The target oscillates left and right with simple harmonic motion. Predict where it'll be when your ball arrives — not where it is now.

Level 4
Bounce Shot

The only path to the elevated target requires a floor bounce first. Elastic collisions and coefficient of restitution in action.

Level 5
Triple Threat

Three targets, one wall, limited shots. Prioritise order, conserve shots, and use the trajectory arc to plan across multiple targets.

Level 6
Gravity Wells

Purple zones increase gravity; cyan zones reduce it. Watch how your trajectory bends and shortens as the ball enters each zone.

Level 7
Air Resistance

Drag is enabled. The ball decelerates in flight — your shots fall short of expectations. Compensate with power, adjust your angle.

Level 8
Chain Reaction

Hit the first target and it will trigger the second via a chain reaction. Use momentum transfer and plan for the cascade.

Level 9
Boss Level

Everything at once: moving target, gravity zones, air resistance, obstacles, and only two shots. The ultimate physics challenge.

Frequently Asked Questions

Is Gravity Lab free to play?↓
Yes, completely free — no account, no download, no ads. Gravity Lab is part of Physics Fundamentals, a free physics education platform.
Does it work on mobile?↓
Yes. Gravity Lab supports touch controls — tap and drag to aim, release to fire. It works on any smartphone or tablet browser.
What physics does the game cover?↓
Gravity Lab covers projectile motion, Newton's laws, elastic collisions, simple harmonic motion, air drag, variable gravity, and conservation of momentum across 9 levels.
Do I need to know physics to play?↓
Not at all. The game is designed to build intuition from scratch. Each level introduces one new concept through gameplay before the next adds complexity.
Can I use this for teaching?↓
Absolutely. Each level is designed around a specific physics concept with an equation overlay and "Did you know?" facts. It's ideal for high school and introductory university physics.
Why does the ball follow a curved path?↓
Because gravity accelerates the ball downward at 9.8 m/s² while its horizontal speed remains constant (ignoring drag). The combination of constant horizontal velocity and accelerating vertical velocity traces a perfect parabola — this is projectile motion.

Keep Learning the Physics Behind This Game

Classical MechanicsProjectile Motion: The Complete GuideRead article →Classical MechanicsWhy Is Projectile Motion a Parabola?Read article →Waves & OpticsSimple Harmonic MotionRead article →KinematicsFree Fall and Terminal VelocityRead article →Classical MechanicsNewton's Laws of MotionRead article →Classical MechanicsMomentum and ImpulseRead article →