Consider a water jar of radius $R$ that has water filled up to height $H$ and is kept on a stand of height h (see figure). Through a hole of radius $r (r << R)$ at its bottom, the water leaks out and the stream of water coming down towards the ground has a shape like a funnel as shown in the figure.If the radius of the cross-section of water stream when it hits the ground is $x$. Then :