A concrete sphere of radius `R` has cavity of radius `r` which is packed with sawdust. The specific
Channel: Doubtnut
Date: 2020-01-19

A concrete sphere of radius `R` has cavity of radius `r` which is packed with sawdust. The specific gravities of concrete and sawdust are respectively `2.4 and 0.3` for this sphere to float with its entire volume submerged under water. Ratio of mass of concrete to mass of swadust will be