A mass of 10kg is suspended from the end of a steel rod of length 4 metres and radius 1mm What is the extension of the rod beyond the original length of y =200 X10-9 N/m²

Question

A mass of 10kg is suspended from the end of a steel rod of length 4 metres and radius 1mm What is the extension of the rod beyond the original length of y =200 X10-9 N/m² 
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