Question

When heated an iron bar expands by 0.2%. If the increase in length is 1 cm, what is the original length of the bar

Answer 1

Let  x be its original length

now when heated it increases by 0.2%

new length = x + 0.2/100(x)

increase in length = new length - x

1 cm = 0.002(x)

x = 1/0.002

=500 cm

so original length = 500 cm

Hope that helps !!

Please mark my answer as Brainliest !

Answer 2

Original Length of the Bar is 5 metre

Step-by-step explanation:

• Let the original length of the bar = 'L' cm

now,

• Increase in length = 0.2% of L = $\frac {0.2}{100} \times L$

As per the question,

Increase in Length is 1 cm  

Which says,

$\frac {0.2}{100} \times L = 1\ cm$

⇒ L = $\frac {100}{0.2}$

⇒ L = $\frac {1000}{2}$

⇒ L = 500 cm or 5 m  (1 m = 100 cm)

Hence, Original Length of the Bar is 5 metre