Question

A box, when hung from a spring balance shows a reading of 50 kg. If the same box is hung form the spring balance inside an evacuated chamber, the reading on the scale will be_____

• A. 50kg because the mass of the box remain unchanged
• B. 50kg because the effect of the absence of the atmosphere will be indentical on the box and the spring balance
• C. Less than 50kg because the weight of the column of air on the box will be absent
• D. More than 50kg because the atmospheric buoyancy force will be absent

Answer 1

The correct option is D More than 50kg because the atmospheric buoyancy force will be absent

A box, when hung from a spring balance shows a reading of 50 kg. If the same box is hung form the spring balance inside an evacuated chamber, the reading on the scale will be more than 50kg because the atmospheric buoyancy force will be absent. As in evacuated chamber in absence of air the air buoyancy is absent and hence shows reading more than the reading in air.