Answer to Question #138593 in Electric Circuits for Faith Sofa

Question

What is meant by saying that a substance is “elastic”? A vertical brass rod of circular section is loaded placing a 5 kg weight on top of it if its length is 50 cm, its radius of cross-section 1 cm, and the Young’s modulus of the material 3.5 x 10^10 Nm-2. Find (a) the contraction of the rod (b) the energy stored in it.

Answer 1

Solution

When we remove external force on a body or material then it come to it's initial position this type material are called elastic.

a) contraction in rod is given by

$\Delta l=\frac{mgl}{\pi r^2Y}$

Putting value of all variable and constants according to data of question

$\Delta l= \frac{5\times9.8\times50\times10^{-2}}{3.14\times1\times10^{-4}\times3.5\times10^{10}}$

$\Delta l=22.29\times10^{-7}m$

b) stored energy is given

$U=\frac{mg\Delta l}{2}$

$U=\frac{5\times9.8\times22.29\times10^{-7} }{2}$

$U=5.46\times10^{-5} J$