waecE-LEARNING
Physics Paper 2, May/June. 2012  
Questions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 Main
General Comments
Weakness/Remedies
Strength
















Question 2

             A spiral spring with a metal extends by 10.5cm in air When the metal Is fully in
water , the spring extends bv 6.8 cm. Calculate the relative density of the metal (Assume Hooke s law Is obeyed)

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comments

This question was poorly attempted and the performance was low. Many candidates tilled to use upthrust which Is (10.5 - 6.8) rather majority of them used 6 8 directly for the division Some candidates erroneously stated that
Relative density = Extension in air
Extension loss in water
The expected answer is:
R.D 38    =    Weight of body in air
               Upthrust (in water)
NOTE: F = kx
=     K(10.5)
    K( 10.5-6.8)
105
3.1
=      2.84


 

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