Frequently Asked Questions
Common questions about the free projectile motion calculator — how it works, what it computes, launch height, the canvas animation, gravity settings, and privacy.
How does the projectile motion calculator work?
Enter your initial speed, launch angle, and starting height, and the tool instantly computes the range, maximum height, time of flight, and impact velocity, then animates the trajectory on a canvas — no button refresh needed. The results and animation update live as you change any input.
Is this calculator free to use?
Yes, it's completely free with no sign-up, downloads, or limits. Run as many scenarios as you like — Earth, Moon, Mars, or any custom gravity. Everything runs in your browser and your inputs are never sent to a server.
What values does it calculate?
It computes four key quantities from your inputs: the horizontal range (how far the projectile travels), the maximum height (the apex of the arc), the total time of flight (from launch to landing), and the impact velocity (the speed at the moment of landing). All four are computed simultaneously and update instantly when you change any value.
Can I launch from a height above the ground?
Yes. The Launch Height input lets you set a starting height above the ground in metres. The calculator accounts for it in the time-of-flight equation — a higher starting point means more time in the air, a longer range, and a higher impact velocity. The trajectory on the canvas also shows the dashed drop from launch height down to the ground.
Does it show the trajectory visually?
Yes. The canvas on the right draws the complete parabolic arc every time the inputs change. Press Play to watch a ball animate along the arc from launch to landing. You can press Stop at any point, or Replay once the animation has finished. Changing the inputs redraws the arc immediately so you can see how angle, speed, or gravity reshapes the trajectory in real time.
Does it account for air resistance?
No. Like most introductory physics models, this calculator assumes ideal projectile motion with no air resistance (drag). That means results match the standard kinematic equations taught in physics courses. Real-world trajectories will differ due to drag, spin, and wind, particularly at high speeds or over long distances.
Can I change the value of gravity?
Yes. The Gravity dropdown lets you choose from four presets — Earth (9.81 m/s²), Moon (1.62 m/s²), Mars (3.72 m/s²), and Jupiter (24.79 m/s²) — or enter a fully custom g value. Selecting Moon gravity, for example, produces a much longer range and flatter arc than on Earth for the same launch conditions.
Is my data stored anywhere?
No. Your inputs are processed entirely in your browser using JavaScript. Nothing is sent to a server, stored in a database, or logged. Close the tab and all your inputs are gone — there is no account, no history, and nothing persisted beyond the current session.
Does it work on mobile devices?
Yes, the tool is fully responsive. The inputs and the canvas stack vertically on small screens so everything stays accessible without horizontal scrolling. The canvas scales to the available width, and the Play button is large enough to tap comfortably on touch screens.
How accurate are the results?
The calculator uses the standard kinematic equations for ideal projectile motion. For a ground-level launch (h₀ = 0), the impact speed equals the launch speed (energy is conserved), complementary angles give equal ranges, and 45° gives the maximum range — all of which you can verify with the tool. Results are displayed to two decimal places, which is consistent with the precision of the inputs.