A steel rod of cross-sectional area `Im^(2)` is acted upon by forces as shown in the Fig. Determine the total elongation of the bar. Take `Y = 2.0xx10^(11) N//m^(2)`

Answer

`01.30`

Explanation

As `I = (FL)/( AY)`
`therefore l _(PQ) = ((60 xx 10 ^(3)) xx 1. 5)/( 1 xx 2 xx 10 ^(1)) = 4. 5 xx 10 ^(-7) m`
`l _(OR) = (( 70 xx 10 ^(3)) xx 1)/( 1 xx 2 xx 10 ^(11)) = 3.5 xx 10 ^(-7) m`
and `l_(RS) = (( 50 xx 10 ^(3)) xx 2)/( 1 xx 2 xx 10 ^(11)) = 5. 0 xx 10 ^(-7) m`
The total extension
`l = 4.5 xx 10 ^(-7) + 3. 5 xx 10 ^(-7) + 5. 0 xx 10 ^(-7)`
`= 13 xx 10 ^(-7) m`
`= 1. 3 xx 10 ^(-6) m`
`therefore l = 1. 3 mu m`