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| Gravitational Potential |
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| The work done in moving a unit mass from infinity to a point in a gravitational field is called the gravitational potential at that point. |
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| It is a negative, scalar quantity. The unit is JKg-1. |
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| The work done in moving a unit mass from one point to another in a gravitational field is called gravitational potential difference. The SI unit is JKg-1. |
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| Let a body of mass m be at a distance r from a body of mass M. The gravitational potential energy of the mass m is defined as the work done in bringing it from infinity to that point. |
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| The work done in moving the mass m through a small distance dr in the gravitational field of M is, |
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| dw = F dr |
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| The total work done in bringing mass m from infinity to that point, is |
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 Gravitational potential energy |
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| If M is the mass of a body around which a field exists and m is the test mass placed at a distance r from M in this field then, |
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| Potential energy per unit mass is gravitational potential (V) |
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The potential energy of a mass m at a height h is given by the
expression  |
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| Considering P.E. at the surface of the Earth to be nil. |
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