We know that the earth exerts a normal force equal to our weight on us . Now if somehow we harness the normal force and use it to do some other work (for example to produce electricity) then what would happen . I mean what effect would it have on us. Would we get deformed due to the exta force as we can't get accelerated downwards as there is the Earth's surface.
[Physics] What happens if the gravitational force mg is greater than the normal force
energynewtonian-gravitynewtonian-mechanics
Best Answer
I think you meant that the surface on which we stand exerts equal and opposite force to balance gravitational pull, which we call as a normal force. If you have this understanding than you are correct about this statement, as it is important to distinguish that it is not the Earth that exerts a normal force, but the surface on which we stand. For example, if you stand on a table that is strong enough to hold you, it prevents you to fall further down as it is strong enough to provide the normal force that will balance your weight. Instead, if you try standing on water, you know what will happen! That's because the surface of the water is not hard enough to provide you with the necessary normal force.
So, here you need to understand that normal force always exists as a response to weight. If you place a 2 g weight on a table, the normal force will be less as compared to placing a 2 kg weight. As you increase the weight of an object placed (consider a bucket kept on the table which is getting filled with water) the normal force will also increase until a point where the surface is not strong enough to hold the object. Just think about this, can you harness any energy from a force whose mere existence is as a consequence of the existence of another force? You can't.
I hope I have understood your question, if not, please elaborate.