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Momentum

Physics: Edexcel IGCSE, topic 1.3.2

Momentum

The momentum of an object is its mass multiplied by its velocity.

Equation for momentum

Equation for momentum

  • The equation for calculating momentum is:
  • p=mvp = mv
  • Momentum = mass × velocity
Units

Units

  • Momentum is measured in kg m/s.
  • Velocity is measured in m/s.
  • Mass is measured in kg.
Conservation of momentum

Conservation of momentum

  • The law of conservation of momentum says that momentum cannot be created or destroyed.
  • If two objects collide, the sum of momentum before the collision is equal to the sum of momentum after the collision.
Equation for the conservation of momentum

Equation for the conservation of momentum

  • The equation for the conservation of momentum is:
  • m1u1+m2u2=m1v1+m2v2m_1u_1 + m_2u_2 = m_1v_1 + m_2v_2
  • (Mass 1 × initial velocity 1) + (mass 2 × initial velocity 2) = (mass 1 × final velocity 1) + (mass 2 × final velocity 2)
  • In other words, the sum of the momentums of the two objects that are colliding will remain the same after they have collided.

Test yourself on Momentum

  • Usain has a mass of 90 kg and he is sprinting at a velocity of 10 m/s. What is his momentum?

  • Serena has a mass of 58 kg and she is sprinting at a velocity of 8 m/s. What is her momentum?

  • What is the equation for the conservation of momentum?

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