Q: One end of a uniform rod of mass m and cross-sectional area A is suspended from a rigid support and an equal mass m is suspended from the other end. The stress at the mid-point of the rod will be
(a) 2mg/(A )
(b) 3mg/(2A )
(c) mg/(A )
(d) None of these
Click to See Answer :
Ans: (b)
Sol: Tension at the mid Point , $\displaystyle T = (m + \frac{m}{2}) g $
$\displaystyle T = \frac{3 m g}{2} $
$\displaystyle Stress = \frac{T}{A} $
$\displaystyle Stress = \frac{ 3 m g}{2 A} $