Question 326: Properties of Matter

Question

The amount of elastic potential energy per unit volume (in SI unit) of a steel wire of length $$100 \mathrm{~cm}$$ to stretch it by $$1 \mathrm{~mm}$$ is (if Young's modulus of the wire $$=2.0 	imes 10^{11} \mathrm{Nm}^{-2}$$ ) :

Accepted Answer

$$
\begin{aligned}
& \frac{	ext { E.P.E }}{	ext { Volume }}=\frac{1}{2}(	ext { stress)(strain) } \
& =\frac{1}{2}(Y)(	ext { strain })^2 \
& =\frac{1}{2}(\mathrm{Y})\left(\frac{\Delta \mathrm{L}}{\mathrm{L}}ight)^2 \
& =\frac{1}{2}\left(2 	imes 10^{11}ight)\left(\frac{1 	imes 10^{-3}}{100 	imes 10^{-2}}ight)^2 \
& =10^5
\end{aligned}
$$

Answer

$$10^{11}$$

Answer

$$10^{17}$$

Answer

$$10^7$$

Answer

$$10^5$$

Properties of Matter

The amount of elastic potential energy per unit volume (in SI unit) of a steel wire of length $100 \mathrm{~cm} to stretch it by 1 \mathrm{~mm} is (if Young's modulus of the wire =2.0 \times 10^{11} \mathrm{Nm}^{-2}$ ) :

Choose the correct answer: