Q. 15.0( 2 Votes )

# A load of 10 kg is suspended by a metal wire 3 m long and having a cross-sectional area 4 mm^{2}. Find (a) the stress (b) the strain and (c) the elongation. Young modulus of the metal is 2.0 × 10^{11} N m^{-2}.

Answer :

(a) 2.5 × 10^{7} N m^{-2}

(b) 1.25 × 10^{-4}

(c) 3.75 × 10^{-4} m

Given, the mass of load,

Length of wire,

cross-sectional area of wire,

Young modulus of the metal,

(a)The stress is given by

Here the force is gravitational in nature.

(b) We know,

The strain is given by

(c) Let the elongation be

The strain is given by

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