Momentum

• What is the equation for calculating momentum?

  p = mv
• What does the variable 'p' represent in the momentum equation?

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

  An object at rest has no momentum
• How does momentum affect the direction of a moving object?

  Momentum keeps an object moving in the same direction
• Why is it difficult to change the direction of an object with large momentum?

  Because it has a significant amount of momentum
• How does the direction of travel affect momentum?

  Momentum depends on the direction of travel since velocity is a vector
• What does it mean for momentum to be positive or negative?

  Positive momentum indicates movement to the right, while negative momentum indicates movement to the left
• When does the momentum of an object change?

  The momentum changes if the object accelerates, decelerates, changes direction, or its mass changes
• What is the relationship between the momentum of a tennis ball and a brick if they have the same momentum?

  Both exert a similar force upon impact

  
• What is the principle of conservation of momentum?

  In a closed system, the total momentum before an event is equal to the total momentum after the event
• What does a closed system mean in the context of momentum?

  A closed system means the energy within the system is constant and there are no external forces
• What happens to the overall momentum of two objects moving in opposite directions at the same speed?

  The overall momentum will be 0 since they cancel out
• What is the momentum of a system before a collision if only one mass is moving?

  The momentum is equal to the mass of the moving object multiplied by its velocity
• How is the total momentum calculated after a collision?

  The total momentum is the sum of the momentum of all objects involved
• What is an elastic collision?

  An elastic collision is when objects collide and move in opposite directions
• What is an inelastic collision?

  An inelastic collision is when objects collide and move in the same direction together
• What is conserved in a collision?

  Momentum is always conserved in a collision
• What should you consider when analyzing a collision in an exam?

  You should consider the motion before and after the collision, including velocities and directions
• What happens to kinetic energy in a perfectly elastic collision?

  The kinetic energy remains the same before and after the collision
• What happens in a perfectly inelastic collision?

  The two objects stick together after colliding
• What can happen to kinetic energy if it is not conserved in a collision?

  Kinetic energy may be converted into heat, sound, or elastic potential energy
• How is momentum calculated before a collision?

  Momentum before the collision must equal momentum after the collision for conservation

  
• If an object of mass 1 kg is traveling at 3 m/s, what is its momentum?

  $p =$$mv =$$1 \times 3 =$$3 \text{ kg m/s}$

  
• How do you calculate the combined velocity of two objects after a collision?

  Use the conservation of momentum principle to find the combined velocity

  
• What is the relationship between force and momentum?

  Force is the rate of change in momentum

  
• What does Δt represent in the context of force and momentum?

  Δt represents the change in time for the force to change momentum

  
• How can the force of an impact in a vehicle collision be decreased?

  By increasing the contact time over which the collision occurs
• What are some safety features designed to reduce impact force in vehicles?

  Crumple zones, seat belts, and airbags

  
• How do crumple zones work in vehicles?

  Crumple zones absorb energy upon impact by changing shape
• What is the purpose of seat belts in vehicles?

  Seat belts keep passengers fixed to their seats during an abrupt stop
• How do airbags help reduce injury during a collision?

  Airbags act as a soft cushion to prevent injury when passengers are thrown forward

  
• What is the function of crash mats in gymnasiums?

  Crash mats help reduce the risk of injury by absorbing shock from falls
• How do cushioned surfaces in playgrounds help children?

  Cushioned surfaces reduce the risk of severe injury by increasing contact time with the ground
• Why might thinner crash mats be suitable for children?

  Because children have lower mass and experience lower impact forces
• What is the limitation of safety features in preventing injuries?

  Safety features reduce the chance of serious injury but do not completely prevent it