Question

A 5 metre long wire is fixed to the ceiling. A weight of `10kg` is hung at the lower end and is `1metre` above the floor. The wire was elongated by `1mm`. The energy stored in the wire duw to streching is
A. zero
B. `0.05joule`
C. `100joule`
D. `500joule`

Answer 1

Correct Answer - B
`W=(1)/(2)xxFxxL=(1)/(2)mgl`
`=(1)/(2)xx10xx10xx1xx10^-1=0.05J`