Three identical point masses are fixed at the corners of an equilateral triangle of…
PHYSICS · Single correct · A Level · Physics · Fields and their consequences · Fields and their consequences
Problem
Three identical point masses m are fixed at the corners of an equilateral triangle of side length L. A fourth mass m is slowly brought from very far away to the centroid (geometric center) of the triangle. Neglect all other forces. Which of the following gives the magnitude of the work that must be done by an external agent to move the fourth mass to the centroid?
(a) L3Gm2
(b) 3Gm2/L
(c) L33Gm2
(d) 23Gm2/L