Answer:
The tension in the thread is approximately 3.2103225 Newtons
Explanation:
The given parameters are;
The side length of the aluminum cube, s = 5 cm
The R.D. of aluminum = 2.7
The relative density of alcohol into which the aluminum cube is placed = 0.8
The volume of the aluminum cube, V = s³ = (5 cm)³ = 125 cm³
The mass of the aluminum cube, V = The volume of the cube
The mass of the aluminum cube, m = V × R.D. × Density of water
m₁ = 0.000125 × 2.7 × 970 = 0.327375 kg
The mass of the alcohol displaced, m₂ = 0.000125 × 0.8 × 970 = 0.097
The tension in the string, T = The apparent weight of the aluminum cube, Wₐ
∴ The tension in the thread, T = Wₐ = (m₁ - m₂) × g
Where;
g = The acceleration due to gravity ≈ 9.81 m/s²
∴ T ≈ (0.327375 - 0.000125) × 9.81 = 3.2103225
The tension in the thread, T ≈ 3.2103225 N.