Question #9ed66

1 Answer
Nov 28, 2016

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=1000kgm3

"acceleration due to gravity "g=9.8ms^-2acceleration due to gravity g=9.8ms2

Wt of displaced water by the object
="Its wt in air"-"wt in water"=Its wt in airwt in water

=320-255=65N=320255=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=6.63×103m3

"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=32.656.63×103kgm3=4924.6kgm3

b) The wt of displaced oil by the object
="Its wt in air"-"wt in oil"=Its wt in airwt in oil

=320-295=25N=320295=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^-3do=25v×g=256.63×103×9.8kgm3

=384.77kgm^-3=384.77kgm3