Materials-Hooke’s Law

• If a spring stretches 1 cm with 1 N, how much will it stretch with 2 N?

  It will stretch 2 cm
• What does Hooke's law state about force and extension?

  Force is directly proportional to extension
• What does *F* represent in the equation $F =$$k\Delta L$?


  Force applied to the spring
• How does a spring behave when pulled gently?

  It stretches a little bit
• What caution should be taken when pulling a spring?

  Do not pull too hard to avoid damage
• Why is it important to stretch a spring gently?

  So it can bounce back and be reused
• What happens to the spring's stretch if the force is doubled?

  The spring's stretch also doubles
• What is Hooke's Law primarily associated with?

  Stretchy toy spring
• What is the consequence of pulling a spring too hard?

  It might break or lose its shape
• What does the gradient of the Force/Extension graph represent?

  The spring constant, k
• What does the equation $F =$$k\Delta L$ imply about the relationship between force and extension?


  Force is directly proportional to extension
• What does a higher spring constant (*k*) indicate about a spring?

  It indicates a stiffer spring
• If the spring constant k* is 2 N/m and the force *F is 4 N, what is the extension ΔL?

  2 m
• What does ΔL indicate in the equation $F =$$k\Delta L$?


  Change in length or extension of the spring
• What does the equation $F =$$k\Delta L$ indicate about force and extension?


  Doubling force doubles the extension
• If the force F* doubles from 4 N to 8 N, what happens to the extension *ΔL?

  It doubles to 4 m
• What is the relationship between the force (F) and the spring constant (k) according to Hooke's Law?

  The force is proportional to the spring constant
• In what units is the spring constant (k) measured?

  Newtons per meter (N/m)
• What is the relationship between k and the force-extension graph?

  k is the gradient of the graph
• What is elastic deformation?

  Change in shape due to applied force
• What does twisting a material do?

  It rotates the material due to applied forces
• How does the extension of a thick rubber band compare to a thin one when the same force is applied?

  The thick band has less extension
• When does the spring constant (k) remain constant?

  Until the elastic limit is reached
• How do elastic deformations differ among materials like springs and rubber bands?

  Different materials exhibit varying elastic responses
• What is the state of the spring shown in the first image?

  Normal
• How can you determine the spring constant, k, from a Force/Extension graph?

  • Calculate the gradient of the graph.
  • Gradient = Force / Extension = F/e
  • Spring constant, k = Gradient
• What happens during compression of a material?

  It shortens due to inward force
• How does changing the spring constant k* affect the extension *ΔL for a given force *F*?

  A higher *k* results in less extension
• What does the spring constant (k) measure?

  Stiffness of the spring
• What does *k* signify in the equation $F =$$k\Delta L$?


  Spring constant, measure of stiffness
• What unit is used for extension in Hooke's Law?

  Meters
• What does the equation $F =$$k\Delta L$ represent?


  Force equals spring constant times extension
• How does the elastic limit relate to the proportional limit?

  The elastic limit is beyond the proportional limit
• What materials can experience elastic deformations?

  • Springs
  • Rubber bands
  • Metal rods
• What are the four states of a spring shown in the image?

  • Normal
  • Compressing
  • Stretching
  • Bending
• What is the 2nd value mentioned in the image?

  Proportional Limit
• What is the formula for Hooke's Law?

  F_spring = -kx
• What happens to the spring when it is compressed?

  The coils of the spring are pushed together
• What happens to the spring when it is stretched?

  The coils of the spring are pulled apart
• What do the variables in Hooke's Law represent?

  • F_spring: Force exerted by the spring
  • k: Spring constant
  • x: Displacement of the spring