Question

how ear aid in balance and position of our body?

Answer 1

ear has a liquid in the semicircular canals, which moves and gives sensation to the haurs present there and gives the brain message about how our head is aligned.
when we turn round and round the liquid also comes in motion and it has momentum which do not stop instantaneously as we stop so we get a dizzy feeling.

Answer 2

that is because ear has 3 fluid present in our ear at 3 direction and each fluid consist of a single cone shape muscles, whenever we move the fluid present in ear also move, that why when we move very fast is circular manner and when we stop we still we feel that we are moving because fluid are still moving inside our ear even though we stop rotating