A) Define pressure and state its SI unit.

Given mass $m = 5 \text{ kg}$ and acceleration due to gravity $g = 10 \text{ N/kg}$.

Length $l = 20 \text{ cm} = 0.2 \text{ m}$
Width $w = 10 \text{ cm} = 0.1 \text{ m}$
Thickness $t = 2 \text{ cm} = 0.02 \text{ m}$

Area 1 ($A_1$) = $l \times w = 0.2 \text{ m} \times 0.1 \text{ m} = 0.02 \text{ m}^2$
Area 2 ($A_2$) = $l \times t = 0.2 \text{ m} \times 0.02 \text{ m} = 0.004 \text{ m}^2$
Area 3 ($A_3$) = $w \times t = 0.1 \text{ m} \times 0.02 \text{ m} = 0.002 \text{ m}^2$

The minimum area ($A_{min}$) is $0.002 \text{ m}^2$.
The maximum area ($A_{max}$) is $0.02 \text{ m}^2$.

Maximum pressure occurs when the force is applied over the minimum area.

D) i) Maximum pressure: $\boxed{25000 \text{ Pa}}$

Minimum pressure occurs when the force is applied over the maximum area.

D) ii) Minimum pressure: $\boxed{2500 \text{ Pa}}$