Let h be the depth at which the rubber ball be taken, Then
P=hρg...(i)
By definition of bulk modulus
B=−PΔV/V
The negative sign shows that with increase in pressure, a decrease in volume occurs.
∴P=BΔVV
Using (i)
hρg=BΔVVorh=BρgΔVV
Substituting the given values, we get
h=(9×108Nm−2103kgm−3×10ms−2)(0.1100)=90m