Given
"wt of the object in air"=320N
"wt of the object in water"=255N
"wt of the object in oil"=295N
We know
"the density of water"= d_w=1000kgm^-3
"acceleration due to gravity "g=9.8ms^-2
Wt of displaced water by the object
="Its wt in air"-"wt in water"
=320-255=65N
So mass of displaced water m_w=65/9.8kg=6.63kg
Volume of displaced water or volume of the object v=m_w/d_w=6.63/1000m^3=6.63xx10^-3m^3
"mass of the object"=m ="its wt"/g=320/9.8kg=32.65kg
a) "density of the object"=d=m/v=32.65/(6.63xx10^-3)kgm^-3=4924.6kgm^-3
b) The wt of displaced oil by the object
="Its wt in air"-"wt in oil"
=320-295=25N
If the density of oil be d_o
then
vxxd_o xxg=25
=>d_o=25/(vxxg)=25/(6.63xx10^-3xx9.8)kgm^-3
=384.77kgm^-3
