Calculate the increases in energy of a brass bar of length 0.4 m and cross-sectional are `1 cm^(2)`. When compressed with a load of 4kg wt along its

Explanation

Here, `l=0.4 m, A=1 cm^(2) = 10^(4) m^(2)`,
`F=4kg wt = 4 xx 10N = 40 N`
`Y=1.0 xx 10^(11)Nm^(2)`
Increasing in energy of brass bar is
`U=1/2 . F. Delta l = 1/2 F xx F/A l/Y [ :. Y= F/A * l/(Delta l)]`
`=(F^(2)l)/(2AY) = ((40)^(2) xx 0.4)/(2 xx 10^(-4) xx (1.0 xx 10^(11)) = 3.2 xx 10^(5)J`.