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Momentum and collisionsPhysicsHigh schoolabout 0:44

What is the momentum of a 70 kg object moving at 9 m/s?: animated lesson

A narrated, step-by-step momentum and collisions video lesson with captions. Final answer: momentum p = 630 kg·m/s.

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Video with a synthetic English voice and captions. Pick another language for subtitles in that language, or open the interactive version.

Video narrated by a synthetic voice (Piper TTS, en_US-ljspeech-high voice (LJ Speech dataset, public domain)); the steps come from our maths engine and the answer was checked independently. Download MP4 (0.3 MB) · Captions (WebVTT)

Steps on screen

1. The problem
Worked example
What is the momentum of a 70 kg object moving at 9 m/s?
2. Step by step
1. $p = mv$
  Formula: momentum
2. $p = (70\ \text{kg})\cdot (9\ \text{m/s}) = 630\ \text{kg·m/s}$
  Substitute the known values
3. The answer
$\text{momentum p = 630 kg·m/s}$
momentum p = 630 kg·m/s
4. Check
- Substituted every value back into the formula: both sides agree ✓

Transcript

The problem. Here is the problem: What is the momentum of a 70 kg object moving at 9 m/s? Use the momentum formula, rearranged for the unknown, in SI units.

Step by step. Formula: momentum. Substitute the known values.

The answer. So the answer is momentum p equals 630 kg times m/s. Momentum is a vector with the same direction as the velocity; in one dimension the sign shows the direction. A 1000 kg car at 20 m/s and a 10 kg ball at 2000 m/s carry the same momentum.

Check. Substituted every value back into the formula: both sides agree, which checks out.

About momentum and collisions

Momentum, impulse and conservation of momentum in collisions.

What is the momentum of a 70 kg object moving at 9 m/s?