Question

Three particles each of mass m are placed at the corners of an equilateral triangle of side d. The potential energy of the systems is

• A.
• B. $\frac { G m ^ { 2 } } { d }$
• C. $\frac { - 3 G m ^ { 2 } } { d }$
• D. None of these

Answer 1

Answer: (C)

$\frac { - 3 G m ^ { 2 } } { d }$

Answer 2

For the system of two particles gravitational energy is given as

U = -Gm₁m₂/r

U_A = U₂ + U₂₃ + U₃₁

U_A = -3 = -

⇒ The answer is (3). –ve sign resembles that the particles are

bounded by their mutual gravitational field.