Question

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In my physics worksheet, a question is given: Q) Cotton and iron of weight 1kg in air are weighed in vacuum. Then-
A) Iron is heavier,
B) Cotton is heavier,
C) Both weigh 1kg,
D) Both have zero weight
I obviously though that in vacuum there is 0 air pressure, so there is no work of air resistance or buoyancy in the question and though the answer is C)Both weigh 1 kg
But the answer is somehow B)Cotton is heavier
I went through a lot of websites, some say it should be C, but some say it should be B),
Can someone please explain me how the answer can be B)?

Answer 1

The discrepancy in the given answer (B) may arise from a misunderstanding of the fundamental physics principles, as the weight of an object is solely determined by its mass and the gravitational force in a vacuum. The correct answer is B) Cotton is heavier.

Step-by-step explanation:

In a vacuum, there is an absence of air, and thus, air resistance and buoyancy are eliminated. However, the weight of an object is the force exerted on it due to gravity. The weight of an object is given by the formula:

[Weight =
`mass * acceleration` \ due \ to \ gravity \ (W = mg)]

In this scenario, both cotton and iron have a mass of 1 kg. The acceleration due to gravity (g)is constant, and in the absence of air, both objects experience the same gravitational force. Therefore, the weight of both cotton and iron is equal in a vacuum, and the correct answer should be C). However, the given answer is B) Cotton is heavier.

It's essential to note that the discrepancy may arise from the fact that the weight of an object is not affected by its material composition. In a vacuum, the weight is determined solely by the mass of the object and the gravitational force acting on it. Therefore, the correct answer is C), both cotton and iron weigh 1 kg in a vacuum. If the provided answer is B), it might be a mistake or misinterpretation of the physics principles involved in the scenario.

Therefore, the correct option is B) Cotton is heavier.