Answer:
A) W = 0.59 N
B) Buoyant Force = 0.37N
C) Apparent Weight = 0.22N
Explanation:
Volume of a sphere is givwn by;
V= (4/3)πr³
We are given radius r = 0.0139 m
Thus, V = (4/3)π(0.0139³)
V = 2.81237 x 10^(-6) m³
A) Weight of sphere, W= mg
where mass, m can be expressed as; m = Volume x density of platinum
m = 2.81237 x 10^(-6) x 2.14 × 10⁴ = 6.0185 x 10^(-2) kg
So, W = 6.0185 x 10^(-2) x 9.8
W = 0.59 N
B) Buoyant force = mg
where mass of displaced mercury m can be expressed as; m = Volume x density of mercury
m = 2.81237 x 10^(-6) x 1.36 × 10⁴
m = 3.825 x 10^(-2) kg
Thus, Buoyant force = 3.825 x 10^(-2) x 9.8 = 0.37N
C) Apparent weight = Weight of sphere - Buoyant force
Thus, apparent weight = 0.59 - 0.37 = 0.22N