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Time of flight
Beginner
Time a projectile stays in the air.
T = 2u sinθ/gFor a launch and landing at the same height, T = 2u sinθ/g. It depends only on the vertical launch component.
At 30 m/s and 53°: T ≈ 2·24/9.8 ≈ 4.9 s.
Time is set by the vertical motion alone; horizontal speed doesn't change it.
In more detail
The time of flight of a projectile launched from ground level and landing at the same level is T = 2u sin θ / g, where u is the launch speed and θ is the launch angle.
Real-world uses
- Estimating how long a javelin stays in the air.
- Predicting the time for a water jet from a fountain to land.
- A goalkeeper or a long jumper uses time of flight to judge how long the ball or body remains airborne.
Open the interactive lesson, with simulation and quiz →
Frequently asked questions
Which angle gives the longest time?
A 90 degree launch, straight up, gives the longest time of flight for a given speed.
Does mass change the time?
Not when air resistance is ignored.
Why is time of flight doubled for level ground?
The projectile rises for half the time and falls for the other half, so the total time is twice the time to the top.
Related topics in Kinematics
Terminal velocity · Two-dimensional motion · Projectile motion · Maximum height · Horizontal range · Complementary angles range