Why gravitational potential energy is taken negative?
Answers
hallo friend.
we take gravitational potential energy as positive when the object is falling towards the earth and when an object is going away from the Earth we take the gravitational potential energy as negative.
thank you!
Energy possessed by an object because of its position in a gravitational field. The zero of gravitational potential energy can be chosen at any point (like the choice of the zero of a coordinate system), the potential energy at a height h above that point is equal to the work which would be required to lift the object to that height with no net change in kinetic energy. Since the force required to lift it is equal to its weight, it follows that the gravitational potential energy is equal to its weight times the height to which it is lifted.
Generally it is equal to the work done against gravity to bring a mass to a given point in space. Because of the inverse square nature of the gravitational force, the force approaches zero for the large distances (infinity) and hence it is appropriate to choose the zero of the gravitational potential energy at an infinite distance. The negative sign indicates that gravity does positive work as mass approaches towards it. The negative potential indicates of the bound state. Which means, once the mass is under its influence its trapped in its potential and if something can provide energy to escape the clutches of gravity it is NOT ALLOWED to escape.
So negative here is indication and not the real number line’s integer section.
One piece of advice: Physics at the outset is philosophy, at the core is mathematics and in between is symbolic. Do not take something too seriously. In quora or wikipedia one can give you the outset or in-between, to understand or to feel physics (especially if you are not mathematically inclined) you got to do the math. Mathematics essentially is unbiased when you study, but when you see it applications in Physics or Engineering or even in Biology in today’s times, you see how Math is the real thing. That is why Kronecker (a Pioneer in Real Analysis) said ““God made the integers, all the rest is the work of man”