Physics (Essay) Paper 2 WASSCE (PC 2ND), 2018

Question 2

 

An archer pulls a bow by 0.7 m with an arrow f mass 60 g.  If the stiffness of the bow is 200 NM-1, calculate the speed of the arrow immediately after its release.

Observation

 

This was popular question among candidates. Many candidates started with the correct formula but fail to convert the 60 g to kg and so made wrong substitution.