Question

A metre scale weighs $50$ grams and carries $20$ grams at one end, the scale balances when it is suspended at a distance x from other endpoints. Then $x$ is equal to?

• A. $35.7cm$
• B. $64.3cm$
• C. $14.3cm$
• D. $50cm$

Answer 1

The correct option is B $64.3cm$

Given,

Length of the scale$=1m$

Now, lets suppose origin at the other end wrt 20g end, and rod to be lied in x-axis

Then,

$x_{com}=\frac{50\times 0.5+20\times 1}{50+20}$

$x_{com}=\frac{45}{70}m$

$x_{com}=\frac{450}{7}cm=64.3cm$

Option $\text{B}$ is the correct answer