P5: Momentum Physics GCSE

• What is the equation for momentum?

  p = mv
• What are the units of momentum?

  kilogram metre per second (kg m/s)
• What happens to the momentum of an object at rest?

  It has no momentum.
• How does momentum affect an object's direction?

  It makes changing direction difficult.
• Why does momentum depend on direction?

  Because velocity is a vector quantity.
• Can momentum be positive or negative?

  Yes, it can be both.
• What indicates negative momentum?

  An object moving to the left.
• When is a tennis ball's momentum negative?

  When it moves opposite its initial direction.
• What factors change an object's momentum?

  • Acceleration (speeds up)
  • Deceleration (slows down)
  • Change in direction
  • Change in mass
• Why do the tennis ball and brick exert similar force on impact?

  Due to their similar momentum.
• What are the units of momentum derived from?

  Product of mass and velocity units.
• What does a closed system mean in momentum conservation?

  Absence of external forces.
• What is the principle of conservation of momentum?

  Total momentum before equals after an event.
• What happens to momentum in a system of objects moving in opposite directions?

  They cancel out to zero momentum.
• What is the momentum of mass m before a collision if moving?


  m × u
• What is the momentum of mass m after a collision if it travels left?

  m × -v
• What is the momentum of mass M after a collision?

  M × V
• What are the types of collisions?

  • Elastic collision: move in opposite directions
  • Inelastic collision: move in the same direction together
• What is conserved in a collision?

  Momentum is always conserved.
• What should you consider when analyzing a collision?

  Motion before and after the collision.
• What characterizes a perfectly elastic collision?

  Kinetic energy is the same before and after.
• What happens in a perfectly inelastic collision?

  Two objects stick together after colliding.
• What energy transfers occur if kinetic energy is not conserved?

  • Converted into heat
  • Converted into sound
  • Converted into elastic potential energy