A non-porous object hangs at rest from a force sensor. Its reading in air is 0.789705 N; when the object is fully submerged in water without touching the vessel, the reading is 0.446355 N. Water density is 1000 kg m⁻³ and g = 9.81 m s⁻². Neglect air buoyancy and surface tension. Find the displaced volume and object density, and predict whether it floats after release. Suggest one check that improves the immersion measurement.

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Volume 3.500 × 10^-5 m³; density 2300 kg m⁻³; it sinks. Remove attached bubbles and keep the object clear of the vessel. The air reading measures mg under the stated approximation. While submerged, upward tension plus buoyant force balances the same weight; the object has not lost mass. The buoyant force is the reading difference, F_b = 0.3433 N. Archimedes' principle gives V = F_b/(ρ_water g) = 3.500 × 10^-5 m³. The mass is W_air/g = 0.0805 kg, hence ρ_object = m/V = 2300 kg m⁻³. Using the unrounded readings avoids unnecessary intermediate rounding. The object's density exceeds water density, so its weight exceeds the largest buoyant force available when fully immersed. Releasing the support therefore makes it sink rather than float. Remove air bubbles, which increase displaced volume without representing the object's own volume. Check that neither the object nor its suspension touches the vessel, since an extra contact force would invalidate the two-force balance.

Infer density from apparent weight · set 1

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