Projectile Motion Calculator
Projectile motion is the motion of an object thrown or projected into the air, subject only to the acceleration of gravity (assuming no air resistance). The object is called a projectile, and its path is called its trajectory. Projectile motion is a form of two-dimensional motion or motion in a plane.
1. Parabolic trajectory (when air resistance is negligible)
2. Constant horizontal velocity (no horizontal acceleration)
3. Constant vertical acceleration (g = 9.81 m/s² downward)
4. Independent horizontal and vertical motions (can be analyzed separately)
Assumptions in ideal projectile motion:
- No air resistance - projectile moves in vacuum
- Constant gravity - g doesn't change with height
- Flat Earth - curvature and rotation effects ignored
- Uniform gravitational field - g is constant in magnitude and direction
- Point mass projectile - no rotation or size effects
Enter initial conditions to calculate complete projectile motion parameters:
- Initial Velocity (v₀): Speed at launch point (m/s, km/h, or mph)
- Launch Angle (θ): Angle from horizontal (0° to 90°)
- Initial Height (h₀): Height above landing surface (0 for ground launch)
- Gravity (g): Acceleration due to gravity (Earth, Moon, Mars, or custom)
The calculator instantly provides:
- Range: Total horizontal distance traveled
- Time of Flight: Total time in air
- Maximum Height: Highest point above launch level
- Impact Velocity: Speed when hitting ground
- Trajectory Equation: Mathematical description of path
- Unit conversions between metric and imperial systems
- Gravity settings for different celestial bodies
Here are typical projectile motion scenarios with calculated values (g = 9.81 m/s²):
| Scenario | Velocity | Angle | Range | Max Height | Time |
|---|---|---|---|---|---|
| Basketball shot | 8 m/s | 60° | 5.66 m | 2.45 m | 1.41 s |
| Football kick | 25 m/s | 45° | 63.70 m | 15.92 m | 3.61 s |
| Golf drive | 70 m/s | 12° | 170.8 m | 8.99 m | 2.48 s |
| Water fountain | 15 m/s | 80° | 7.77 m | 11.32 m | 3.01 s |
| Catapult shot | 40 m/s | 30° | 141.4 m | 20.39 m | 4.08 s |
| Moon golf shot | 70 m/s | 45° | 1,730 m | 433 m | 61.3 s |
For maximum range from ground level: θ = 45°. For maximum range with initial height h₀: θ < 45°. Complementary angles (30° and 60°, 15° and 75°) give same range (from ground level) but different heights and times.
Below are answers to frequently asked questions about projectile motion calculations and applications:
The range equation is R = (v₀²·sin(2θ))/g. Since sin(2θ) has maximum value of 1 when 2θ = 90°, therefore θ = 45° gives maximum range.
Range R(θ) = (v₀²/g)·sin(2θ)
dR/dθ = (2v₀²/g)·cos(2θ) = 0 for maximum
cos(2θ) = 0 → 2θ = 90° → θ = 45°
This assumes launch from ground level. With initial height, optimal angle is less than 45°.
Practical note: In sports, optimal angle is often less than 45° due to air resistance, height of release, and target height. Baseball optimal ~30°, basketball ~48°, golf ~12°.
Air resistance (drag) makes calculations complex, requiring numerical methods:
F_drag = ½·ρ·v²·C_d·A
Where: ρ = air density, C_d = drag coefficient, A = cross-sectional area
Horizontal: dvₓ/dt = -(ρ·C_d·A/(2m))·v·vₓ
Vertical: dvᵧ/dt = -g - (ρ·C_d·A/(2m))·v·vᵧ
These differential equations require numerical integration (Euler, Runge-Kutta methods).
Effects of air resistance: Reduces range (20-50% for sports balls), lowers trajectory, makes landing angle steeper. Terminal velocity limits maximum speed for falling objects.
Understanding projectile motion gives athletes competitive advantages:
| Sport | Optimal Angle | Key Physics | Strategy |
|---|---|---|---|
| Basketball | 45-48° | Release height matters (2m) | Higher arc = larger target area |
| Football (soccer) | 20-30° | Air resistance significant | Knuckleballs, curves via spin |
| Golf | 10-15° | Maximize carry distance | Low launch + backspin = longer roll |
| Baseball | 25-35° | Home run optimization | Launch angle + exit velocity critical |
| Shot Put | 38-42° | Release height ~2.1m | Less than 45° due to height |
| Long Jump | 20-25° | Take-off velocity ~9-10 m/s | Horizontal speed prioritized |
Modern sports use high-speed cameras and computer analysis to optimize launch parameters. Baseball's "launch angle revolution" increased home runs by optimizing to 25-30°.
Projectile motion principles are critical for artillery, missiles, and space launches:
- Artillery: Range tables account for air density, wind, Earth rotation (Coriolis effect)
- Missile guidance: Real-time trajectory corrections using GPS and inertial navigation
- Space launches: Rocket equations combine with projectile motion for orbital insertion
- Ballistic missiles: Suborbital trajectories with ranges up to 15,000 km
- Satellite deployment: Precise velocity and angle calculations for specific orbits
- Re-entry vehicles: Ballistic coefficients for atmospheric re-entry
Example: ICBM with 7 km/s velocity, 25° launch angle has range ≈ 10,000 km. Atmospheric drag reduces this to practical ranges of 5,000-15,000 km.
At velocities approaching orbital velocity (~7.8 km/s for Earth), projectile motion merges with orbital mechanics:
- Suborbital: v < 7.8 km/s - returns to Earth (ballistic missiles)
- Low Earth Orbit: v ≈ 7.8 km/s - circular orbit just above atmosphere
- Escape velocity: v ≥ 11.2 km/s - leaves Earth's gravity well
- Geostationary: v ≈ 3.07 km/s at 35,786 km altitude
Projectile equations fail at orbital speeds because they assume flat Earth and constant g. Need orbital mechanics (Kepler's laws).
Interesting fact: If you throw a ball at 7.9 km/s horizontally from sea level (ignoring air), it would orbit Earth at ground level! Actually air friction would vaporize it instantly.
Different gravity significantly affects projectile motion:
| Celestial Body | Gravity (m/s²) | Range Multiplier | Time Multiplier | Human Jump Example |
|---|---|---|---|---|
| Earth | 9.81 | 1× | 1× | 0.5 m vertical jump |
| Moon | 1.62 | 6.06× | 2.46× | 3.0 m vertical jump |
| Mars | 3.71 | 2.64× | 1.62× | 1.3 m vertical jump |
| Jupiter | 24.79 | 0.40× | 0.63× | 0.2 m vertical jump |
| Pluto | 0.62 | 15.8× | 3.98× | 7.9 m vertical jump |
Range is inversely proportional to g. Moon's low gravity (1/6 Earth) means 6× longer jumps. On Jupiter (2.5× Earth gravity), you could barely jump. Use our calculator's gravity selector to experiment!