A semicircular wire and a semicircular lamina both have radius R. Their common centre is at the origin and both lie above the x-axis. Which statements are correct?
Select all that apply

Question

A semicircular wire and a semicircular lamina both have radius R. Their common centre is at the origin and both lie above the x-axis. Which statements are correct?

G1 Physics · Accepted Answer

For a uniform semicircular wire, symmetry gives x(CM)=0 and y(CM)=2R/π. For a uniform semicircular lamina, x(CM)=0 and y(CM)=4R/(3π). Since 2/π > 4/(3π), the wire's centre of mass is farther from the circle centre. Both lie on the common symmetry axis. Therefore A, B, C and D are correct.