Physics
posted by Elisa .
Can't get correct answer
An object weighing 340 N in air is immersed in water after being tied to a string connected to a balance. The scale now reads 260 N. Immersed in oil, the object weighs 290 N.
(a) Find the density of the object.
kg/m3
(b) Find the density of the oil.
kg/m3

The volume of water displaced weighs 80 N, and has a mass of 80 N/g = 8.16 kg. That amount of water occupies 8.16 liters, or 8.16*10^3 m^3, and equals the volume of the object. So the object's density is
[340 N/g]/8.16*10^3 m^3
= 4250 kg/m^3
The weight reduction in oil is 5/8 of the weight reduction in water, so the oil has 50/80 of the density of water, or 625kg/m^3