Results are for reference only. This ignores air resistance — real projectiles fall shorter and steeper. Good for intuition, not ballistics.
Engineering · mechanics

Projectile Motion

Throw, launch or fire something and see where it lands.
no drag · constant g
45° · 20 m/s

Launch

aim & fire
20 m/s
45°
0 m

Trajectory

speed
Flight
Detail
Field notes

What governs the flight

How it works

Two motions at once

A projectile does two independent things at the same time: it moves sideways at constant speed (nothing pushes it horizontally) and it accelerates downward under gravity. Splitting the launch into those two components — horizontal v·cosθ and vertical v·sinθ — is the whole trick. Press launch to watch them combine into the familiar arc.

Worked example

Throw a ball at 20 m/s and 45° from ground level. It flies for 2.9 s, peaks at 10.2 m, and lands 40.8 m away — and hits the ground at the same 20 m/s it left, just angled downward.

The neat result: on flat ground, 45° gives the maximum range, and any two angles that add to 90° (say 30° and 60°) land in the same spot.

Why does 45° go farthest?

Range depends on the product of horizontal speed and hang time. Lower angles have more horizontal speed but less hang time; higher angles the reverse. 45° balances them — on level ground. Launch from a height and the best angle drops below 45°.

Does mass matter?

Not here. Without air resistance, all projectiles follow the same path regardless of mass — a cannonball and a pebble launched identically land together. Add drag and that changes.

How wrong is "no air resistance"?

For dense, slow, heavy objects over short distances, barely. For light objects, high speeds, or long ranges, very — real range can be a fraction of the ideal. Treat this as the frictionless ideal.

What changes on the Moon?

Gravity is about ⅙ of Earth's, so the same throw goes roughly six times farther and stays up about 2.5× longer. Switch the gravity buttons to see it.