Question

The length of a metal wire is 10cm when the
tension in it is 20N and 12cm when the tension
is 40N. Then natural length of the wire is in
ANSWER IS 8
please explain with clear answer ​

Answer 1

Answer:

8cm

Explanation:

We will use a concept called Young's Modulus to answer this question.

Young's Modulus = Y

Y = (Force/Area*Change in Length)

Young's modulus is always constant for a material.

So the two equations can be equated like this

20/Area*(10-l)=40/Area*(12-l)

we can cancel Area and the forces

12-l = (10 - l)*2

12 + l = 20

l = 8

Therefore we conclude the original length to be 8 cm.