Q19 A mild steel wire of length 1.0 m and cross-sectional area is stretched, well within its elastic limit, horizontally between two pillars. A mass of 100 g is suspended from the mid-point of the wire. Calculate the depression at the midpoint.
Let the ends of the steel wire be called A and B.
length of the wire is 2l = 1 m.
The cross-sectional area of the wire is
Let the depression at the midpoint due to the suspended 100 g be y.
Change in the length of the wire is
The strain is
The vertical components of the tension in the arms balance the weight of the suspended mass, we have
The stress in the wire will be
The Young's Modulus of steel is
The depression at the mid-point of the steel wire will be 1.074 cm.