Impulse Calculator (J = mΔv = FΔt)
Impulse Calculator (J = mΔv = FΔt)
The impulse-momentum theorem states that impulse (a force applied over time) equals the change in momentum. Enter the object's mass and its velocity before and after, plus the time over which the change happened, and this calculator computes both the impulse and the average force involved.
Because impulse equals both mass times velocity change AND average force times time, knowing any one relationship lets you solve for the other — a 2 kg object speeding up from 0 to 10 m/s has an impulse of 20 N·s, and if that change happened over 0.5 seconds, the average force involved works out to 40 N. This is exactly the physics behind why airbags and crumple zones reduce injury in a crash: they extend the time over which the same momentum change happens, which directly reduces the average force experienced, since the impulse itself (determined by the mass and velocity change) stays the same either way.
- Impulse J = m × Δv, so a 2 kg object speeding up from 0 to 10 m/s has an impulse of 2 × 10 = 20 N·s.
- Impulse also equals average force × time (J = F × t), so given the time over which the impulse acted, you can find the average force: 20 N·s / 0.5 s = 40 N.
- The force-time graph's shaded area equals the impulse - this is the same "area under the curve" idea used throughout physics, here applied to a constant average force.
How do I calculate impulse?
Multiply the mass by the change in velocity: J = m × (vf - vi).
What is the impulse on a 2 kg object that speeds up from 0 to 10 m/s?
J = 2 × (10 - 0) = 20 N·s.
Impulse Calculator (J = mΔv = FΔt)
The impulse-momentum theorem states that impulse (a force applied over time) equals the change in momentum. Enter the object's mass and its velocity before and after, plus the time over which the change happened, and this calculator computes both the impulse and the average force involved.
Because impulse equals both mass times velocity change AND average force times time, knowing any one relationship lets you solve for the other — a 2 kg object speeding up from 0 to 10 m/s has an impulse of 20 N·s, and if that change happened over 0.5 seconds, the average force involved works out to 40 N. This is exactly the physics behind why airbags and crumple zones reduce injury in a crash: they extend the time over which the same momentum change happens, which directly reduces the average force experienced, since the impulse itself (determined by the mass and velocity change) stays the same either way.
- Impulse J = m × Δv, so a 2 kg object speeding up from 0 to 10 m/s has an impulse of 2 × 10 = 20 N·s.
- Impulse also equals average force × time (J = F × t), so given the time over which the impulse acted, you can find the average force: 20 N·s / 0.5 s = 40 N.
- The force-time graph's shaded area equals the impulse - this is the same "area under the curve" idea used throughout physics, here applied to a constant average force.
How do I calculate impulse?
Multiply the mass by the change in velocity: J = m × (vf - vi).
What is the impulse on a 2 kg object that speeds up from 0 to 10 m/s?
J = 2 × (10 - 0) = 20 N·s.