Question

You take a bucket outside and hold it as you normally would to hold water. As the rain comes down, the flux of water out of the bucket is Incorrect: Your answer is incorrect. . If you were to then cut out the bottom of the bucket and again hold it in the rain, the flux of water out of the bucket would be (postive, negative, zero) ?

Answer 1

Answer:

• the bucket-surface area vector and the direction of the rain is 180° which gives a negative flux in the outward direction.

• If we cut the base of the bucket then hold it in the rain then the there is no area intercepted by the rainfall and hence we have a zero flux.

Explanation:

We know that flux is defined as the density of any energy field passing through a given area parallel to the area vector.

Mathematically:

$\phi=\bar E.A\cos\theta$

where:

$\phi=$ flux through the area

$A=$ area of concern

$\bar E=$ density of energy field per unit area

$\theta=$ angle between the energy field lines and the normal to area.

When we hold a bucket in the rain then assuming that the base of the bucket is normal to the direction of rainfall then the angle between the area vector and the rain drop is zero when observed from inside.

• For the flux outside the bucket we are concerned with the outer surface of the bucket, now the angle formed between the bucket-surface area vector and the direction of the rain is 180° which gives a negative flux in the outward direction.

• If we cut the base of the bucket then hold it in the rain then the there is no area intercepted by the rainfall and hence we have a zero flux.