Two wires of diameter 0.25 cm, one made of steel and the other made of brass are loaded as shown in Fig. 9.13. The unloaded length of steel wire is 1.5 m and that of brass wire is 1.0 m. Compute the elongations of the steel and the brass wires.
Diameter of the wires = 0.25 cm
That is, ds = dB = 0.25 cm
Radius of the wires will be given by,
Unloaded length of the steel wire, Ls=1.5 m
Unloaded length of the brass wire, LB = 1 m
Young's modulus of steel, Ys = 2 Pa
Young's modulus of brass, YB =
m1 = 4 kg and m2 = 6 kg
Brass wire is under a tension of load 6 kg.
Therefore, increase in length is given by
Since, brass wire is under a tension of load 6 kg.
Adhesive force is the attractive force between two unlike molecules. They are caused by forces acting between two substances like electrostatic force (attraction due to opposing charges), mechanical force etc.
E.g., Force of attraction between gum and paper.
Inter-atomic or inter-molecular forces are electrostatic in nature.