A sphere of mass of m = 1.69 kg is first placed directly on the plate of an electronic scale. The scale shows 16.58 N as the weight of the object. A large beaker containing a liquid with a density of 783 kg/m^3 is then placed on the scale and the scale is tared (i.e. zeroed to this weight as a reference point, it has a reading of zero with the beaker on the scale). The sphere, hung by a thin string, is lowered into the liquid and submerges below the surface. The scale reads 2.19 N with the sphere not touching the beaker. Calculate the density of the sphere.
My work so far:
F_buoyant = 16.58N - 2.19N = 14.39
F_buoyant = (Rho_liquid)(g)(V_liquid displaced)
14.39N = (783kg/m^3)(9.81m/s^2)(V_liquid displaced)
V_liquid displaced = 0.001873398 m^3 = 0.00187 m^3
So the density of the sphere:
rho_sphere = m_sphere/V_sphere
V_sphere = V_liquid displaced = 0.00187 m^3
rho_sphere = 1.69kg/0.00187m^3
= 902.1040911 kg/m^3
= 902 kg/m^3
... which is what I got for the final answer but apparently it is incorrect. If there is anything, what did I do wrong?
1 answer