HomeEveryday PhysicsProjectile Motion Simulator - Trajectory, Range, Angle and Air Resistance

🧪 Projectile Motion Simulator - Trajectory, Range, Angle and Air Resistance

Interactive projectile motion simulator for GCSE and A-Level physics. Adjust launch angle, initial speed, and air resistance to explore parabolic trajectories. Compare trajectories on Moon, Earth, Mars and Jupiter.

Everyday Physics2DModerate60 FPS💨 Air & Wind
projectile-motion-simulator-trajectory-range-angle-and-air ↗ Open standalone

The Physics of Projectile Motion

Projectile motion is the motion of an object launched into the air subject only to gravity (and optionally air resistance). Because horizontal and vertical motion are independent, we can analyse them separately — one of Newton's most powerful insights in kinematics.

📈 Core Equations (No Air Resistance)

For launch speed v₀, angle θ, and gravitational acceleration g:

  • Horizontal: x = v₀ cos θ · t
  • Vertical: y = v₀ sin θ · t − ½ g t²
  • Range: R = v₀² sin 2θ / g
  • Max Height: H = v₀² sin²θ / (2g)
  • Time of Flight: T = 2 v₀ sin θ / g

These assume launch and landing at the same height. The simulator also supports an elevated launch height.

△ The 45° Optimal Angle

The range equation R = v₀² sin 2θ / g is maximised when sin 2θ = 1, i.e. 2θ = 90°, giving θ = 45°. This is the complementary angle principle — pairs such as 30° & 60°, 20° & 70°, etc. produce the same range.

With a non-zero launch height above the landing point, the optimal angle shifts below 45°. With air resistance it also shifts below 45°, because drag affects the trajectory asymmetrically.

Try comparing 30° and 60° in the simulator — notice identical ranges but different flight times and peak heights!

🋻 Air Resistance (Drag)

Real projectiles experience drag force opposing motion. In this simulator linear drag is modelled: F_drag = −k · v, where k is a drag coefficient. This modifies the equations of motion:

  • ẍ = −(k/m) · vₓ
  • ÿ = −g − (k/m) · v_y

The analytical solution involves exponential decay terms; the simulator uses Euler integration with a small time step. Air resistance makes the trajectory non-symmetric: the descent is steeper than the ascent, and both range and maximum height are reduced.

🌎 Gravity on Other Worlds

Surface gravity, g = GM/R², depends on mass M and radius R:

  • 🌙 Moon: g ≈ 1.62 m/s² — projectiles fly ~6× farther!
  • 🌏 Earth: g ≈ 9.81 m/s² — our reference
  • 🪐 Mars: g ≈ 3.72 m/s² — ~38% of Earth
  • 🪰 Jupiter: g ≈ 24.79 m/s² — short, steep arcs

Apollo astronauts famously hit golf balls enormous distances on the Moon, and Mars missions must account for the lower gravity when planning rover driving and landing trajectories.

Equations of Motion — Derivation

Newton's second law applied separately to horizontal (x) and vertical (y) directions, with no air resistance:

QuantityHorizontal (x)Vertical (y)
Accelerationaₓ = 0a_y = −g
Velocityvₓ = v₀ cos θv_y = v₀ sin θ − g t
Positionx = v₀ cos θ · ty = y₀ + v₀ sin θ · t − ½ g t²
Speed|v| = √(vₓ² + v_y²)
Angle of velocityφ = arctan(v_y / vₓ)

At maximum height, v_y = 0, so t_peak = (v₀ sin θ) / g. Substituting into y(t) gives H = v₀² sin²θ / (2g). The projectile lands when y = 0 again (for y₀ = 0) at time T = 2 t_peak, giving range R = vₓ · T = v₀² sin 2θ / g.

Real-World Applications

Projectile motion governs an enormous range of physical phenomena beyond simple ball-throwing:

⚽ Sport Science

Ball sports require optimising launch angle and speed: a football kicked at 45° will travel the maximum horizontal distance (ignoring spin and air effects), while javelin throwers aim for ~35° because the release point is above the landing point. Golf club design, batting power, and shot-put technique all involve projectile optimisation.

🚀 Space & Rocketry

Early ballistic missiles follow projectile trajectories through the upper atmosphere. The first intercontinental ballistic missiles (ICBMs) had ranges determined by launch angle and speed — exactly the equations in this simulator. Orbital mechanics generalises projectile motion when the range becomes large enough that Earth's curvature is significant.

🌞 Fountains & Irrigation

Water jets, sprinkler systems, and fire hoses all obey projectile equations. Engineers designing irrigation systems calculate where the water stream will land based on nozzle angle and pressure (initial speed). Fountain designers use parabolic jets to create specific visual patterns.

🔞 Forensic Ballistics

Forensic scientists reconstruct crime scenes using projectile motion — given the entry point and angle of a bullet hole, they can calculate the shooter's position. Blood-spatter analysis also uses the equations of an ejected droplet following a ballistic arc to determine impact location and direction.

Curriculum Coverage

QualificationTopic / ModuleRelevant Concepts
GCSE PhysicsForces & MotionSpeed, velocity, acceleration; horizontal and vertical components of motion
A-Level Physics / Maths (Mechanics)Kinematics; ProjectilesEquations of motion SUVAT, parabolic trajectories, resolving vectors, range equation
IB Physics (SL/HL)2.1 Motion; Option B MechanicsProjectile motion, independence of horizontal/vertical, air resistance
AP Physics 1Kinematics, Unit 1Two-dimensional kinematics, projectile equations, maximum range at 45°
University (Year 1)Classical MechanicsEuler/Runge-Kutta integration, drag models, numerical vs analytical solutions

Frequently Asked Questions

What angle gives the maximum range?

Without air resistance, 45° always gives maximum range on flat ground. This follows because R = v₀² sin 2θ / g is maximised when sin 2θ = 1, i.e. 2θ = 90°. With air resistance the optimum angle shifts slightly below 45° — try it in the simulator!

Why are the trajectories parabolic?

Constant horizontal velocity (no horizontal force) gives x ∝ t, while constant downward acceleration gives y ∝ t². Eliminating t gives y as a quadratic function of x — the definition of a parabola. On a rotating Earth or over very long distances, the trajectory deviates from a perfect parabola.

Do 30° and 60° really give the same range?

Yes! Since sin(2 × 30°) = sin 60° = sin 120° = sin(2 × 60°), the range formula gives identical values for complementary angles (θ and 90°−θ). However, the 60° shot reaches a higher peak and takes longer. Try both in the simulator to confirm!

How is air resistance modelled here?

This simulator applies linear drag: deceleration = k × speed, where k is a fixed drag coefficient (0.05 s⁻¹). The equations are integrated numerically using Euler steps at dt = 0.01 s. Real-world drag is often quadratic (F ∝ v²), which gives a more pronounced effect at high speeds.

Can I use this for my GCSE or A-Level revision?

Absolutely. The simulator directly illustrates the key GCSE and A-Level concepts: independence of horizontal and vertical motion, the range/height equations, the 45° optimum angle, and the effect of air resistance. Set specific values and compare the HUD readouts with hand-calculated answers using SUVAT equations.

⚙ Under the hood

This simulation models the trajectory of a projectile, taking into account factors like angle, range, air resistance, and gravity. It allows users to explore the physics behind projectile motion.

Projectile MotionAir Resistance

2D · HTML5 Canvas 2D · 60 FPS target · runs fully client-side, no install

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