SSC
PHYSICS
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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mgh2
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mgh
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1/2mgh
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1/2mv2
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Detailed explanation-1: -The formula for potential energy depends on the force acting on the two objects. For the gravitational force the formula is P.E. = mgh, where m is the mass in kilograms, g is the acceleration due to gravity (9.8 m / s2 at the surface of the earth) and h is the height in meters.
Detailed explanation-2: -Let’s consider an object taken to a height ‘h’ from the surface of the earth. When, h«R, then, R + h = R and g = GM/R2. On substituting this in the above equation we get, Gravitational Potential Energy U = mgh.
Detailed explanation-3: -If the object is lifted straight up at constant speed, then the force needed to lift it is equal to its weight mg. The work done on the mass is then W = Fd = mgh. We define this to be the gravitational potential energy (PEg)put into (or gained by) the object-Earth system.
Detailed explanation-4: -The value of gravitational potential is given by, V =-GM/R.