Given
"wt of the object in air"=320Nwt of the object in air=320N
"wt of the object in water"=255Nwt of the object in water=255N
"wt of the object in oil"=295Nwt of the object in oil=295N
We know
"the density of water"= d_w=1000kgm^-3the density of water=dw=1000kgm−3
"acceleration due to gravity "g=9.8ms^-2acceleration due to gravity g=9.8ms−2
Wt of displaced water by the object
="Its wt in air"-"wt in water"=Its wt in air−wt in water
=320-255=65N=320−255=65N
So mass of displaced water m_w=65/9.8kg=6.63kgmw=659.8kg=6.63kg
Volume of displaced water or volume of the object v=m_w/d_w=6.63/1000m^3=6.63xx10^-3m^3v=mwdw=6.631000m3=6.63×10−3m3
"mass of the object"=m ="its wt"/g=320/9.8kg=32.65kgmass of the object=m=its wtg=3209.8kg=32.65kg
a) "density of the object"=d=m/v=32.65/(6.63xx10^-3)kgm^-3=4924.6kgm^-3density of the object=d=mv=32.656.63×10−3kgm−3=4924.6kgm−3
b) The wt of displaced oil by the object
="Its wt in air"-"wt in oil"=Its wt in air−wt in oil
=320-295=25N=320−295=25N
If the density of oil be d_odo
then
vxxd_o xxg=25v×do×g=25
=>d_o=25/(vxxg)=25/(6.63xx10^-3xx9.8)kgm^-3⇒do=25v×g=256.63×10−3×9.8kgm−3
=384.77kgm^-3=384.77kgm−3