A platinum sphere with radius 0.0135 0.0135 m is totally immersed in mercury. Find the weight of the sphere, the buoyant force acting on the sphere, and the sphere's apparent weight. The densities of platinum and mercury are 2.14 × 10 4 2.14×104 kg/m3 and 1.36 × 10 4 1.36×104 kg/m3, respectively.

Respuesta :

Answer:

W=2.2 N

F=1.4 N

W'=0.8 N

Explanation:

Given that

Radius ,r = 0.0135 m

Density of the platinum ,ρ₁ = 2.14 x 10⁴ kg/m³

Density of the mercury ,ρ₂ = 1.36  x 10⁴ kg/m³

The weight of the sphere

W= m g

mass = m = volume x density

[tex]m=\dfrac{4}{3}\pi r^3\times \rho_1\ kg[/tex]

[tex]m=\dfrac{4}{3}\times \pi\times 0.0135^3\times 2.14\times 10^4\ kg[/tex]

m = 0.22 kg

W= 0.22 x 10 = 2.2 N   (↓)           ( take g =10 m/s²)

The buoyant force

[tex]F= \dfrac{4}{3}\pi r^3\times \rho_2\times g[/tex]

[tex]F=\dfrac{4}{3}\times \pi\times 0.0135^3\times 1.36\times 10^4\times 10[/tex]

F= 1.4 N  (↑)

The  apparent weight

W' = 2.2 - 1.4 N

W'= 0.8 N