Question

A homogeneous plate $P Q R S T$ is as shown in figure. The centre of mass of plate lies at midpoint $A$ of segment $Q T$. Then the ratio of $\frac{b}{a}$ is $(P Q=P T=b ; Q R=R S=S T=a)$

• A. $\frac{13}{4}$
• B. $\frac{13}{2}$
• C. $\sqrt{\frac{13}{2}}$
• D. $\sqrt{\frac{13}{4}}$

Answer 1

Answer: (D)

If centre of mass is at $A$
$a^{2} \sigma \frac{a}{2}=\sigma \frac{1}{2} a b \sin \theta \frac{1}{3} b \sin \theta$

or $\quad \frac{b}{a}=\sqrt{\frac{13}{4}}$