Projectile Motion Simulator
Simulate projectile motion with adjustable launch angle and speed. Visualize trajectory, calculate range, max height, and time of flight interactively.
About Projectile Motion
Projectile motion describes the curved path of an object launched into the air and moving under gravity alone (ignoring air resistance). The key insight is that horizontal and vertical motions are completely independent of each other.
Two Independent Components
- Horizontal (x): Constant velocity — no acceleration. vₓ = v₀ cos θ remains unchanged throughout.
- Vertical (y): Uniform downward acceleration. vᵧ starts at v₀ sin θ and decreases by g each second.
Key Variables
| Symbol | Name | Unit | Description |
|---|---|---|---|
| v₀ | Initial Speed | m/s | Speed at the moment of launch |
| θ | Launch Angle | ° | Angle above the horizontal |
| g | Gravitational Acceleration | m/s² | 9.8 m/s² on Earth; 1.6 m/s² on Moon |
| R | Range | m | Horizontal distance from launch to landing |
| H | Maximum Height | m | Highest point above the launch level |
| T | Time of Flight | s | Total time the projectile is in the air |
| t | Elapsed Time | s | Time since launch at any instant |
| x(t) | Horizontal Position | m | Horizontal distance at time t |
| y(t) | Vertical Position | m | Height at time t |
Worked Example 1 — Range at 45°
Ball launched at v₀ = 30 m/s, θ = 45°, g = 9.8 m/s²:
Worked Example 2 — Maximum Range
Range is maximised when sin(2θ) = 1, i.e., 2θ = 90°, so θ = 45°. Complementary angles (e.g. 30° and 60°) always give the same range because sin(2 × 30°) = sin(2 × 60°).
Tips for Using the Simulator
- The dashed blue arc is the predicted full trajectory — it updates instantly as you move sliders.
- The orange ball with the green trail shows the simulated path during animation.
- Blue arrow = vₓ (constant horizontal velocity). Pink arrow = vᵧ (decreases to zero at peak, then reverses).
- The Predicted panel on the right shows R, H, and T before you even launch.
- After landing, the ball rests at the exact calculated range — compare with the predicted value.
Key Formulas
| Formula | Description | Notes |
|---|---|---|
| x(t) = v₀ cosθ · t | Horizontal position | Constant velocity — no x-acceleration |
| y(t) = v₀ sinθ · t − ½gt² | Vertical position | Parabolic — rises then falls |
| R = v₀² sin2θ / g | Range | Maximum at θ = 45° |
| H = v₀² sin²θ / (2g) | Maximum height | Reached when vᵧ = 0 |
| T = 2v₀ sinθ / g | Time of flight | Twice the time to peak |
| vₓ = v₀ cosθ | Horizontal velocity | Constant throughout flight |
| vᵧ = v₀ sinθ − gt | Vertical velocity | Zero at max height |
Equation of Motion (Horizontal)
Equation of Motion (Vertical)
Range, Max Height, Time of Flight
Velocity Components at Any Time t
Resultant Speed
Frequently Asked Questions
What angle gives maximum range in projectile motion?
45° gives the maximum range on flat ground (in the absence of air resistance), because sin(2 × 45°) = sin(90°) = 1, its maximum value.
Does a heavier object land sooner than a lighter one?
No. In the absence of air resistance, all objects fall at the same rate regardless of mass. Both would follow identical trajectories if launched with the same initial speed and angle.
Why is the path parabolic?
Because x increases linearly with time while y is a quadratic function of time. Eliminating t from x(t) and y(t) gives y as a quadratic function of x — the equation of a parabola.
Why do 30° and 60° give the same range?
Because sin(2 × 30°) = sin(60°) and sin(2 × 60°) = sin(120°) = sin(60°). Complementary launch angles always produce the same range.
What is the speed at maximum height?
At maximum height vᵧ = 0, so the speed equals the horizontal component: v₀ cosθ. This is the minimum speed during the entire flight.