OCR MEI Further Mechanics B AS 2021 November — Question 1

Exam BoardOCR MEI
ModuleFurther Mechanics B AS (Further Mechanics B AS)
Year2021
SessionNovember
TopicWork, energy and Power 2

1 The end O of a light elastic string OA is attached to a fixed point.
Fiona attaches a mass of 1 kg to the string at A . The system hangs vertically in equilibrium and the length of the stretched string is 70 cm . Fiona removes the 1 kg mass and attaches a mass of 2 kg to the string at A . The system hangs vertically in equilibrium and the length of the stretched string is now 80 cm . Fiona then removes the 2 kg mass and attaches a mass of 5 kg to the string at A . The system hangs vertically in equilibrium.
  1. Use the information given in the question to determine expected values for
    • the length of the stretched string when the 5 kg mass is attached,
    • the elastic potential energy stored in the string in this case.
    Fiona discovers that, when the mass of 5 kg is attached to the string at A , the length of the stretched string is greater than the expected length.
  2. Suggest a reason why this has happened.