5.7.1 Momentum

• What is the definition of momentum in physics?

  Momentum is the quantity of motion an object has.
• Why is momentum considered a vector quantity?

  Because it has both magnitude and direction.
• How does understanding momentum help in analyzing collisions?

  It explains how forces affect the motion of objects during collisions.
• What is the formula for calculating momentum?


  p = m · v
• What does \( p \) represent in the momentum formula?

  Momentum
• What units are used to express momentum?

  Kilograms meters per second (kg·m/s)
• What does \( m \) represent in the momentum formula?

  Mass of the object (in kilograms, kg)
• What does \( v \) represent in the momentum formula?

  Velocity of the object (in meters per second, m/s)
• What is the principle of conservation of momentum?

  In a closed system with no external forces, the total momentum before an event equals the total momentum after the event.
• How would you use the conservation of momentum principle in a collision between two cars?

  You would set the total momentum of the two cars before the collision equal to the total momentum after the collision.
• What is the first example problem involving momentum in the study material?

  A car with a mass of 1000 kg traveling at a velocity of 20 m/s.
• What is the momentum of a car with a mass of 1000 kg traveling at 20 m/s?

  20,000 kg·m/s
• What is the second example problem involving momentum in the study material?

  A cyclist with a mass of 70 kg moving at a speed of 5 m/s.
• What is the momentum of a cyclist with a mass of 70 kg moving at a speed of 5 m/s?

  350 kg·m/s
• How is the change in momentum related to force and time?

  The change in momentum is equal to the force applied multiplied by the time the force acts.
• What is the formula for calculating change in momentum?

  Change in Momentum = F · t
• What does impulse represent in relation to momentum?

  Impulse is equal to the change in momentum.
• What are elastic collisions?

  In elastic collisions, both momentum and kinetic energy are conserved.
• Give an example of an elastic collision.

  Two billiard balls colliding and bouncing off each other.
• What are inelastic collisions?

  In inelastic collisions, momentum is conserved, but kinetic energy is not.
• Give an example of an inelastic collision.

  A car crash where the vehicles crumple and generate heat and sound.
• What is the first practical example problem involving momentum in the study material?

  Two ice skaters pushing off each other.
• In the ice skater example, what is the total momentum after they push off each other?

  0 kg·m/s
• What does it indicate if the total momentum before and after a collision is not the same?

  It indicates an error in the assumed data or interpretation.
• What is the second practical example problem involving momentum in the study material?

  A ball of mass 0.5 kg traveling at 4 m/s hitting a stationary ball of mass 0.3 kg.
• What is the total momentum before the collision in the second example problem?

  2 kg·m/s
• What is the total momentum after the collision in the second example problem?

  1.9 kg·m/s
• What does the summary state about momentum?

  Momentum is the product of mass and velocity and is a vector quantity.
• What does the summary state about the conservation of momentum?

  The total momentum before an event equals the total momentum after in a closed system.
• What does the summary state about change in momentum?

  Change in momentum equals force applied times time.
• What does the summary state about collisions?

  Momentum is conserved in both elastic and inelastic collisions, but kinetic energy is only conserved in elastic collisions.
• Why is understanding momentum important?

  It helps analyze various physical interactions, from everyday objects to complex systems.