forces and elasticity

• What must be applied to change the shape of stationary objects?

  Multiple forces
• How can objects change their shape?

  By stretching, bending, or compressing
• What happens during compression?

  Forces act towards the object
• What are the two forces involved in compression of a spring?

  The weight of the mass and reaction force
• How is an object stretched?

  Forces act away from the object
• What are the two forces involved in stretching a spring?

  The weight of the mass and tension in the spring
• How does bending occur?

  Multiple forces act at different points
• What are the two forces involved in bending a diving board?

  The weight of the swimmer and reaction force
• What is elastic distortion?

  When objects return to original shape
• What materials undergo elastic distortion?

  Rubber bands, fabrics, steel springs
• What is inelastic distortion?

  When objects do not return to original shape
• What materials undergo inelastic distortion?

  Plastic, clay, glass
• What does Hooke's Law describe?

  The relationship between force and extension
• What does Hooke's Law state?

  Extension is directly proportional to force
• What happens if the force is doubled according to Hooke's Law?

  The extension will also double
• What is the limit of proportionality?

  The point where force and extension are no longer proportional
• What is the equation for Hooke's Law?

  F = k × x
• What does the spring constant represent?

  How stiff a spring is
• How is extension calculated?

  Final length – Original length
• What does the term $x^2$ mean in the elastic potential energy equation?


  Extension is squared in calculations
• What is the equation for elastic potential energy?


  E = ½ kx²
• What happens to elastic potential energy if extension is doubled?

  Work done is quadrupled
• What is the aim of the experiment investigating force and extension?

  To investigate the relationship between force and extension
• What is the independent variable in the experiment?

  Force, F
• What is the dependent variable in the experiment?

  Extension, x
• What is the resolution of the measuring equipment used?

  1 mm for the ruler
• What should be done before taking the reading of the spring's length?

  Wait for the spring to fully extend
• What is a systematic error in the experiment?

  Measurements taken at eye level
• What is a random error in the experiment?

  Using a fiducial marker for accuracy
• What safety precautions should be taken during the experiment?

  Wear goggles and secure the clamp stand
• What should be done if the spring exceeds its limit of proportionality?

  It will stop obeying Hooke's law
• What is the formula to calculate weight?

  W = mg
• How is the force calculated in the experiment?

  By multiplying mass by gravitational field strength
• What should be plotted to analyze the results of the experiment?

  A graph of force against extension
• What indicates that a spring obeys Hooke's law on a graph?

  A linear region represented by a straight line
• What is a common mistake when calculating extension?

  Calculating increase in length instead of total extension