A body of mass 11kg is suspended from a ceiling fan by an aluminum wire of length 2m and diameter 2mm. Calculate the elastic energy stored in the wire [Young's modulus of aluminum is 7.0 x 1010Nm-2, g = 10ms-2, \(\pi\) = 3.142]`
A. 1.1 x 10-1J B. 5.5 x 10-2J C. 1.1 x 10-4J D. 5.5 x 10-8J
Correct Answer: B
Explanation
e = \(\frac{4FI}{Y \pi d^2} = \frac{4 \times 11 \times 10 \times 2}{7 \times 10^3 \times 3.14(2 \times 10^{-2})^2}\) = 0.001m E = \(\frac{1}{2} Fe = \frac{1}{2} \times 110 \times 0.001\) = 5.5 x 10-2J
