If we leave a iron ball and feather into the water, feather returns to the surface and floats or moves into the water slowly. On the other hand, iron ball (of certain mass greater than mass of feather) moves into the water directly. Here, both iron ball and feather are accelerated towards the earth to the same extent. Then why does feather moves slowly into the water than iron ball? Shouldn't they reach the earth at the same time.
If we assume that water medium is making the feather to accelerate to lesser extent than iron ball, then doesn't it mean gravitational force is affected by intervening medium?
Similarly if we consider a feather and iron ball to be left from certain height, I hope iron ball reaches the earth first and then feather. The reason I think is because of air resistance, doesn't this mean air medium or intervening medium is affecting gravitational force?
We know that gravitational force is not affected by intervening medium, but it is contrary to the above situations. Is it that gravitational force is affected by intervening medium?
I might have misunderstood sometimes, if so, pardon me and explain.