Question

From a uniform circular plate of radius R, a small circular plate of radius R/4 is cut off, as shown. If O is the centre of the complete plate, then at what distance from O, does the new centre of mass of the remaining plate lie.

• A. – R/20
• B. – R/16
• C. – R/15
• D. –R/12

Answer 1

Answer: (A)

– R/20

Answer 2

m = (pR²t)d Ž Mass of plate µR²

M₁r₁ = $\frac{M}{16} \times \frac{3R}{4}$Ž $r = \frac{- R}{20}$