Question

Two bodies of masses 5kg and 15kg are located in the cartesian plane at (1,0) and (0,1). What is the location of their centre of mass?

(a) 1/4, 1/4

(b) 3/4, 3/4

(c) 3/4, 1/4

(d) 1/4, 3/4

This question was addressed to me during an internship interview.

Question is taken from System of Particles in division System of Particles and Rotational Motion of Physics – Class 11

Answer 1

The correct answer is (d) 1/4, 3/4

The best I can explain: Sum of masses = 5 + 15 = 20

x-coordinate;

(5*1 + 15*0)/20 = 1/4

y-coordinate;

(5*0 + 15*1)/20 = 3/4.