Energy Conservation

• What happens to a metal wire when loaded beyond its limit of proportionality?

  It undergoes plastic deformation
• What occurs when the force is removed from a metal wire that has undergone plastic deformation?

  The extension decreases but remains permanent
• How does the unloading line compare to the loading line in a force-extension graph?

  It is parallel but does not pass through the origin
• What does it indicate if a wire is permanently deformed?

  It will not return to zero extension
• What does the area between the loading and unloading lines represent in a force-extension graph?

  Work done to permanently deform the wire

  
• What are the key features of the force-extension graph for a rubber band?

  • No permanent extension when fully unloaded
  • Stores more strain energy when loaded than unloaded
  • Contraction curve is below the stretching curve
• What does area X represent in the force-extension graph of a rubber band?

  Work done in heating the rubber

  
• What does area Y represent in the force-extension graph of a rubber band?

  Work done by the rubber returning to shape

  
• What does the sum of areas X and Y represent in the rubber band graph?

  Work done in stretching the rubber band
• What happens to a rubber band when it is stretched and contracted?

  It becomes warm due to energy transfer
• What components make up vehicle suspension systems?

  Tires, springs, and shock absorbers

  
• What effect does a bump in the road have on a vehicle's wheel?

  The wheel moves up and down
• What happens if a wheel loses contact with the road surface?

  It slams back down causing vibrations
• How do shock absorbers contribute to vehicle comfort?

  They absorb impact forces from bumps
• What do shock absorbers convert kinetic energy into?

  Thermal energy which is dissipated
• How does the speed of springs affect shock absorber resistance?

  The faster they move, the more resistance
• What is the relationship between loading and unloading in a rubber band?

  Loading stores more energy than unloading