question_answer

A metal sheet 14 cm x 2 cm of uniform thickness is cut into two pieces of width 2 cm. The two pieces are joined and laid along XY plane as shown. The centre of mass has the coordinates  

A) (1, 1)

B) (7/2, 7/2)            

C)      (13/4, 9/4)

D) (12/7, 8/7)   

Correct Answer: C

Solution :

[c] \[{{X}_{cm}}=\frac{m\times 5.5+1\times m}{2m}=\frac{6.5}{2}=\frac{13}{4}cm.\] \[{{Y}_{cm}}=\frac{m\times 3.5+1\times m}{2m}=\frac{4.5}{2}=\frac{9}{2}cm.\]