A piece of cork whose weight is 19 gm is attached to a bar of silver weighing 63 gm. The two together just not in water. The specific gravity of silver is 10-5. Find the specific gravity of the cork. Density of water = `1 gm cm ^(-3)`

Explanation

Density of silver ` = 10.5 gm cm ^(-3)`
`" " ` Mass of cork = `m_1= 19 gm `
`" "` Mass of silver `= m_2 = 63 gm`
Total mass of floating body = ` m_1+ m_2 = 82 gm `
Mass of floating body = mass of water displaced
` therefore ` Mass of displaced = ` ("mass " )/( " density") = (82)/(1) = 82 cm ^(3)`
Volume of silver `= (" mass")/(" density") = ( 63)/( 10.5) = 6 cm ^(3)`
Volume of cork = Total Volume - Volume of silver
` " " = 82- 6= 7^(2) cm ^(3)`
Density of cork = ` (" mass ")/( " volume") = (19)/(76) = 0.25 gm cm ^(-3)`
Specific gravity = ` (" density of cork")/( " density of water ") = (0.25 gm cm ^(-3))/( 1 gm cm ^(-3)) = 0.25`