A homogeneous plate `PQRST` is as shown in figure. The centre of mass of plate lies at midpoint `A` if segment `QT`. Then the ratio of `(b)/(a)` is `(PQ = PT = b , QR = RS = ST = a)`
.

Options

A. `(13)/(4)`
B. `(13)/(2)`
C. `sqrt((13)/(2))`
D. `sqrt((13)/(4))`

Answer

D

Explanation

(d) If centre of mass is at `A`
`a^2 sigma (a)/(2) = sigma (1)/(2) ab sin theta (1)/(3) b sin theta`
or `(b)/(a) = sqrt((13)/(4))`
.