Required Practical 6:Stretching a Spring

• What should you be able to describe by the end of the video?

  Investigate the relationship between force and extension
• Why is it important to learn the details of this practical?

  It is a required practical
• What equipment is used in the investigation?

  Clamp stand, bosses, clamps, meter rule, spring
• Why must the meter rule be vertical?

  To ensure accurate readings
• What is attached to the bottom of the spring?

  A wooden splint as a pointer
• What is the unstretched length of the spring?

  The length with no force attached
• What weight is first hung on the spring?

  One newton weight
• How do you calculate the extension produced by each weight?

  Subtract unstretched length from each reading
• What is the extension produced by the 1 Newton weight?

  4 cm
• What is the extension produced by the 2 Newton weight?

  8 cm
• What is the extension produced by the 3 Newton weight?

  12 cm
• What is the extension produced by the 4 Newton weight?

  16 cm
• What do you plot against the weight on the graph?

  Extension
• What does the straight line graph indicate about the relationship between force and extension?

  • Extension is directly proportional to weight
  • This indicates a linear relationship
  • Linear means straight line
• What happens to the graph when using a rubber band?

  It does not produce a straight line
• What does it mean if the spring is elastic?

  Extension returns to zero when weight is removed
• What occurs if too much weight is added to the spring?

  The graph becomes nonlinear
• What is inelastic deformation?

  Extension remains after weight is removed
• What is the limit of proportionality?

  The maximum weight before nonlinear behavior
• How is the spring constant determined from the graph?

  By dividing force by extension
• What equation is used to calculate the force required to extend a spring?

  Force = spring constant × extension
• When is the spring constant the same for any part of the graph?

  As long as we don't exceed the limit of proportionality
• What can you find plenty of questions on this required practical?

  • Vision workbook
  • Available via a link