What is an advantage of using wind for producing electricity instead of coal?
a) a lot of energy is produced by wind compared to coal
b) obtaining wind does not harm the environment, but obtaining coal does
c) using wind is less expensive than using coal
d) wind is abundant in certain areas, and coal is not abundant

Hello there!

A) a lot of energy is produced by wind compared to coal

This is not really true, it would depend on wind disponibility and a lot of other things like that.

B) obtaining wind does not harm the environment, but obtaining coal does

This is true, "obtaining" wind does not harm the environment, while the coal requires mining.

C) using wind is less expensive than using coal

This can differ in different locations, there are a lot of variables that can impact the prices. Yes, the wind is "free", but the machines needed to transform wind into energy not, so there may be situations where wind is more expensive than using coal.

D) wind is abundant in certain areas, and coal is not abundant

False, coal is also abundant in some areas.

t = 1/400 h   ⇔ 0.0025 h ⇔ 9s ⇔ 0.15 m

any of the answers are correct.