$1)$ We know, Diagonal of rhombus is proportional to its side.

$\Rightarrow$ Cor-responding ratio of diagonals $=5: 3: 2$

Let them be $5 y, 3 y, \&$ 2y respectively as shown in figure.

$2)$ Now,

$V_{A_{3}}-V_{A_{o}}=\frac{d\left(A_{o} A_{3}\right)}{d t}$

$=>V-0=\frac{d(10 y)}{d t}$

$=>V-0=10 \frac{d y}{d t}….(1)$

$3)$ Also, $V_{A_{3}}-V_{A_{2}}=\frac{d\left(A_{3} A_{2}\right)}{d t}$

$=>V-V_{A_{2}}=\frac{d(2 y)}{d t}$

$=>V-V_{A_{2}}=2 \frac{d(y)}{d t}….(2)$

Elimination $\frac{d y}{d t}$ from above equations, we get

$V_{A_{2}}=0.8 \mathrm{V}$

Hence, Velocity at $A_{2}$ is $0.8 V$