4.1.17

Momentum

Test yourself

Momentum and Impulse

The momentum of an object is its mass multiplied by its velocity (p = mv).

Illustrative background for Impulse = change in momentumIllustrative background for Impulse = change in momentum ?? "content

Impulse = change in momentum

  • The change in momentum of an object is equal to the impulse applied to it.
  • Impulse = change in momentum (Δp).
Illustrative background for Impulse equationIllustrative background for Impulse equation ?? "content

Impulse equation

  • Impulse = force x time.
  • Δp = F x t.
Illustrative background for Conservation of momentumIllustrative background for Conservation of momentum ?? "content

Conservation of momentum

  • The law of conservation of momentum says that momentum cannot be created or destroyed.
    • So, if two objects collide, the sum of momentum before collision = sum of momentum after collision.
Illustrative background for Change in momentum = mv - muIllustrative background for Change in momentum = mv - mu ?? "content

Change in momentum = mv - mu

  • Change in momentum = mv - mu, where m is mass, u is the initial velocity of an object and v is the final velocity of an object.

Force and Momentum Change

When a force acts on an object that is moving, or able to move, a change in momentum happens. Force equals the rate of change of momentum. This can be shown by combining two equations:

Illustrative background for Acceleration and momentumIllustrative background for Acceleration and momentum ?? "content

Acceleration and momentum

  • acceleration = change in velocity ÷ time taken.
    • a = Δv ÷ t.
Illustrative background for Force and accelerationIllustrative background for Force and acceleration ?? "content

Force and acceleration

  • Force = mass × acceleration.
    • F = m x a.
Illustrative background for Force = rate of change of momentumIllustrative background for Force = rate of change of momentum ?? "content

Force = rate of change of momentum

  • Combining the 2 equations we get F = m x Δv ÷ t.
  • F = m Δv ÷ t.
  • F = Δp ÷ t.
  • Force = change in momentum ÷ change in time.
  • In other words, force is equal to the rate of change of momentum.

Jump to other topics

1Measurements & Errors

2Particles & Radiation

3Waves

4Mechanics & Materials

5Electricity

6Further Mechanics & Thermal Physics (A2 only)

7Fields & Their Consequences (A2 only)

8Nuclear Physics (A2 only)

9Option: Astrophysics (A2 only)

10Option: Medical Physics (A2 only)

11Option: Engineering Physics (A2 only)

12Option: Turning Points in Physics (A2 only)

Go student ad image

Unlock your full potential with GoStudent tutoring

  • Affordable 1:1 tutoring from the comfort of your home

  • Tutors are matched to your specific learning needs

  • 30+ school subjects covered

Book a free trial lesson