Lesson 20.3

• Collision


  An event where two objects exchange impulse and momentum
• Types of collision


  • Elastic collision
  • Inelastic collision
• Elastic collision


  Occurs when the total kinetic energy of the system remains the same
• Perfectly elastic collision


  When the two objects completely bounce off each other
• Collision


  An event where two objects exchange impulse and momentum
• Inelastic collision


  Occurs when the total kinetic energy of the system changes after collision due to loss of some energy
• Types of collision


  • Elastic collision
  • Inelastic collision
• Perfectly inelastic collision


  When two objects collide and they stick together as one body and have the same velocity after collision
• Elastic collision


  Occurs when the total kinetic energy of the system remains the same
• Perfectly elastic collision rarely occurs in real life
• Perfectly elastic collision


  When the two objects completely bounce off each other
• Inelastic collision


  Occurs when the total kinetic energy of the system changes after collision due to loss of some energy
• Most collisions are inelastic
• Elastic collision


  • The total kinetic energy remains the same after collision
• Perfectly inelastic collision


  When two objects collide and they stick together as one body and have the same velocity after collision
• Inelastic collision


  • The total kinetic energy changes after collision
• Perfectly elastic collision rarely occurs in real life
• Mass and velocity of objects in a collision


  Determine the damages or effects
• Most collisions are inelastic
• Large impact forces


  May cause large damages and injuries
• Elastic collision


  • The total kinetic energy remains the same after collision
• Small impact forces


  May cause only dents and slight injuries
• Inelastic collision


  • The total kinetic energy changes after collision
• Larger vehicles


  Cause more damage than smaller vehicles
• Mass and velocity of objects in a collision

  Determine the damages or effects
• Truck and motorcycle crash against a wall with the same speed

  Greater damage on the wall where the truck crashes compared to the wall where the motorcycle crashes
• Large impact forces


  May cause large damages and injuries
• Momentum


  Also called as the inertia in motion. The larger is the object, the larger is the momentum for objects with the same velocity
• Small impact forces


  May cause only dents and slight injuries
• Increase in an object's mass

  Increases the momentum of the object
• Larger vehicles


  Cause more damage than smaller vehicles
• Faster object


  Larger momentum, more difficult to stop
• Truck and motorcycle crash against a wall with the same speed

  Greater damage on the wall where the truck crashes compared to the wall where the motorcycle crashes
• Two cars with equal mass but different velocity collided with a wall

  The faster car would cause more damage
• Momentum


  Also called as the inertia in motion. The larger is the object, the larger is the momentum for objects with the same velocity
• Republic Act No. 8750 requires the mandatory use of seat belt devices in all vehicles
• Increase in an object's mass

  Increases the momentum of the object
• Seatbelts and airbags


  • Decrease the possible injuries by increasing the time of contact between the body and steering wheel
• Faster object

  Larger momentum, more difficult to stop
• Other safety devices installed in cars

  • child restraint seats
  • pre-collision system
  • safety glass