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Grade 11Mechanics

The height from the surface of earth at which the gravitational potential energy of a ball of mass m is half of that at the centre of Earth is (where R is radius of earth)

a) R/4

b) R/3

c) 3R/4

d) 4R/3

Profile image of Arnab Mandal
14 Years agoGrade 11
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5 Answers

Profile image of Swapnil Saxena
14 Years ago

The gravitational Potential energy of the particle at the center of the earth is (3/2)(GMm/R) . So the Height must be

(1/2)*(3/2)(GMm/R) (Potential Energy of the Particle at the center/2) =GMm/X (Potential Energy of the Particle at a height) = 4R/3. ---Ans

Profile image of Arnab Mandal
14 Years ago

Answer is (b).

Profile image of Arnab Mandal
14 Years ago

Answer is (b). Now Solve correctly and please post the detailed calculation.

Profile image of Swapnil Saxena
14 Years ago

There is nothing wrong in the solution .Actually 4R/3 is the distance of the point from the center of the earth and R/3 from the surface.

Profile image of Arnab Mandal
14 Years ago

Thank you. You were correct. Now please solve the "thermoprob" ones!!!!!!!