Physics Paper 2 WASSCE (PC), 2019

 

Question 4

 

The elastic cord of a catapult has a cross-sectional area of 10 mm2 and unstretched length of 10 cm. It is stretched to 15.0 cm and then released to project a missile of mass 5.0 g. Calculate the energy stored in the cord.

Observation

This question was popular among candidates. Few candidates who attempted this question performed woefully. Performance was low.
The expected answer is :
Calculation of the energy stored in the elastic cord