HOOKES LAW

1
HOOKES LAW

• Chapter 18

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Elasticity Hookes Law

• Elasticitythe property of a body by which it
  experiences a change in shape when a deforming
  force acts on it, and by which it returns to its
  original shape when the deforming force is
  removed
• Materials that do not return to their original
  shape are call inelastic
• Elastic limitthe distance at which permanent
  distortion occurs in an elastic material
• Hanging a weight on a spring causes it to stretch
• The amount the spring stretches is dependent upon
  the amount of mass on the spring

3
Hookes Law

• Hookes Law the amount of stretch/compression of
  a spring is directly proportional to the applied
  force
• Felastic kx
• k spring constant (units N/m)
• x displacement (units m)
• Hookes law holds as long as the spring is not
  compressed beyond its elastic limit

4
Hookes Law

• A 76 N crate is hung from a spring (k 450 N/m).
  How much displacement is caused by the weight
  of this crate?
• A spring of k 1962 N/m loses its elasticity if
  stretched more than 50.0 cm. What is the mass of
  the heaviest object that the spring can support
  without being damaged?