How can one easily discern the renal cortex from the renal medulla?

The renal medulla is made generally out of gathering conduits and the nephron circles. You won't perceive any glomeruli in the medulla, as they are kept to the cortex. This makes the renal cortex and renal medulla effortlessly recognizable.

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When the ball is rising up, it gains kinetic energy. when the ball reaches the very top, it will have all potential energy, until it falls back down and gains it kinetic energy. finally when you catch the ball or it falls back down, it would have gained its potential energy back.