Question

Four identical spheres each of radius $10$ $cm$ and mass $1$ $kg$ each are placed on a horizontal surface touching one another so that their centers are located at the corners of square of side $20$ $cm.$ What is the distance of their center of mass from center of either sphere?

• A. $5cm$
• B. $10\sqrt{2}cm$
• C. $20cm$
• D. $Noneoftheabove$

Answer 1

The correct option is B $10\sqrt{2}cm$

Finding $CM$ of both horizontal pair of spheres

And then the $CM$ of the centre of mass will be in the middle to the sphere

Then finding distance of $CM\left(4kg\right)$ from centre of either sphere

Thus distance is $10\sqrt{2}cm$