Four identical 1 kg particles sit at corners of a square of side 2√2 m. After one is removed, centre of mass shifts by x/y m in lowest terms. Find x.
Physics · Mixed Chapter
JEE Main Practice

Question

Four identical 1 kg particles sit at corners of a square of side 2√2 m. After one is removed, centre of mass shifts by x/y m in lowest terms. Find x.

G1 Physics · Accepted Answer

Step 1: Original centre is square centre. Distance of any corner from centre =side/√2=(2√2)/√2=2 m. Step 2: If one mass is removed from four identical masses, the remaining three centre shifts opposite that corner by 1/(4−1) of its initial position vector. Step 3: Magnitude of shift =2/3 m. Thus x=2.