Vertical Velocity Calculator

Projectile motion is the motion of an object launched into the air, subject only to the force of gravity (ignoring air resistance). The object follows a curved parabolic trajectory, with its horizontal velocity staying constant and its vertical velocity changing due to gravitational acceleration.

Vertical velocity is the component of a projectile's velocity acting in the upward or downward direction. At launch, it equals Vy₀. As the projectile rises, gravity decelerates it; it reaches zero at the peak, then increases downward on descent. It is calculated using Vy = Vy₀ − g·t.

Use the formula Vy = Vy₀ − g·t, where Vy₀ is the initial vertical velocity in m/s, g is the gravitational acceleration (9.81 m/s² on Earth), and t is the elapsed time in seconds. A positive result means the projectile is still moving upward; a negative result means it is moving downward.

The standard formula is Vy = Vy₀ − g·t. You can rearrange it to find any unknown: Initial velocity Vy₀ = Vy + g·t, gravity g = (Vy₀ − Vy) / t, and time t = (Vy₀ − Vy) / g.

On Earth, the standard acceleration due to gravity is 9.81 m/s² (sometimes approximated as 9.8 or 10 m/s²). For the Moon use 1.62 m/s², for Mars use 3.72 m/s², and for Jupiter use 24.79 m/s².

A projectile reaches maximum height when its vertical velocity equals zero. Setting Vy = 0 in the formula gives t_peak = Vy₀ / g. For example, with an initial vertical velocity of 30 m/s on Earth, the peak is reached at 30 / 9.81 ≈ 3.06 seconds.

Horizontal velocity remains constant throughout the flight (no horizontal force acts on the projectile, ignoring air resistance), while vertical velocity continuously changes due to gravitational acceleration. The two components are independent of each other.

Yes. A negative initial vertical velocity means the projectile was launched downward (e.g., thrown off a cliff toward the ground). The calculator handles both positive (upward launch) and negative (downward launch) values for Vy₀.