Question Detail
Question
A piece of wood with a density of 705 kg/m³ is tied with a string to the bottom of a water-filled flask. The wood is completely immersed, and has a volume of 8.00 × 10⁻⁶ m³. What is the tension in the string?
Correct Answer
Option B is the correct answer.
Detailed Explanation
Buoyant force = ρ_water × V × g = 1000 × 8×10⁻⁶ × 9.8 = 0.0784 N. Weight = ρ_wood × V × g = 705 × 8×10⁻⁶ × 9.8 = 705 × 7.84×10⁻⁵ = 0.0553 N. Tension = buoyant force - weight = 0.0784 - 0.0553 = 0.0231 N ≈ 0.0234 N.
Hint
Tension = buoyant force - weight when object is submerged and tied to bottom.