Physics CP13 Forces and Matter

• What is the definition of extension in the context of a spring?

  The extension of a spring is the change in length when a force is applied to it.
• What does Hook's law state about the extension of a spring?

  Hook's law states that the extension of a spring is directly proportional to the force applied.
• If you double the force applied to a spring, what happens to the extension?

  The extension also doubles.
• What does a straight line graph of force against extension indicate?

  It indicates a directly proportional relationship between force and extension.
• What type of relationship is shown on a graph for a spring's extension and force?

  A linear relationship shown as a straight line through the origin.
• How do springs and rubber bands behave when forces are applied?

  Both stretch when forces are applied to them.
• Compare and contrast the behavior of springs and rubber bands under force.

  • Springs: Follow Hook's law, exhibit linear behavior.
  • Rubber bands: Do not follow Hook's law, exhibit non-linear behavior.
• What is the difference between bending and stretching?

  Bending involves changing shape without changing length, while stretching involves increasing length.
• What does the term 'elastic' mean in materials science?

  'Elastic' refers to materials that return to their original shape after the force is removed.
• How can elastic deformation be utilized in sports?

  Elastic deformation can be used in sports equipment to store and release energy.
• What is the difference between elastic and plastic deformation?

  Elastic deformation is reversible, while plastic deformation is permanent.
• What happens to hands when they are gently squeezed?

  They change shape but return to their original shape when the pressure is released.
• What is an example of elastic deformation in everyday objects?

  Bending a steel rule slightly and it returning to its previous shape.
• What is plastic deformation?

  Plastic deformation is a permanent change in shape when a force is applied.
• What happens when a metal wire is bent sharply?

  It is less likely to return to its original shape after the force is removed.
• What is an example of a material that can be easily and permanently deformed?

  Modelling clay.
• How do tendons in our bodies behave as elastic materials?

  Tendons store elastic potential energy when running and release it when slowing down.
• What is the extension of a spring when a 1N weight is hung from it?

  The extension is 2 cm.
• What will the extension be when the weight is 0.5N?

  The extension will be 1 cm.
• How can you explain your answer regarding the extension when the weight is 0.5N?

  The extension is half of that with 1N, assuming linearity.
• How would you measure the extension of a spring accurately?

  By using a ruler to measure the change in length before and after applying the weight.
• How does the force and extension relationship change for a spring?

  The relationship is linear, resulting in a straight line graph.
• How does the force and extension relationship change for a rubber band?

  The relationship is non-linear, resulting in a curve graph.
• What is the formula for Hooke's law?

  F = kx
• What does the variable 'k' represent in Hooke's law?

  'k' represents the spring constant.
• What is the formula for work done in stretching a spring?

  W = \frac{1}{2}kx^2
• What is elastic potential energy?

  Elastic potential energy is the energy stored in a spring when it is stretched or compressed.
• How is energy transferred when a spring is released?

  Energy is transferred to launch a projectile or cause a mousetrap to snap shut.
• What does a larger value of the spring constant 'k' indicate?

  A larger value indicates a stiffer spring that requires more force to stretch.
• How does a stiffer spring behave in terms of energy storage?

  A stiffer spring will store more energy for a given amount of extension.
• What is the unit of the spring constant?

  The unit of the spring constant is Nm⁻¹.
• What is the relationship between the extension of a spring and the height reached by a mass?

  The extension of the spring affects the height reached by the mass when released.
• How do you calculate the energy transferred when a mass is released from a spring?

  Using the equation $E =$$mgh$.
• What does the variable 'g' represent in the energy transfer equation?

  'g' represents the acceleration due to gravity, approximately $9.81 \text{ m/s}^2$.
• What conclusions can be drawn from the relationship between the extension of the spring and the height reached by the mass?

  As the extension increases, the height reached by the mass also increases.