A regular concrete block weighing 5kg, has dimensions 8cm x 20cm x 50cm . Calculate the greatest possible pressure the block will exert on the ground.[g=10m/s ]

The force is the weight of the block, which is mass multiplied by the acceleration due to gravity.

$$F = m \times g$$ $$F = 5 \text{ kg} \times 10 \text{ m/s}^2$$ $$F = 50 \text{ N}$$

To exert the greatest pressure, the block must rest on its smallest face. The dimensions are 8 cm, 20 cm, and 50 cm. The smallest area will be formed by the two smallest dimensions.

$$A_{min} = 8 \text{ cm} \times 20 \text{ cm}$$ $$A_{min} = 160 \text{ cm}^2$$

Since $1 \text{ m} = 100 \text{ cm}$, then $1 \text{ m}^2 = (100 \text{ cm})^2 = 10000 \text{ cm}^2$.

$$A_{min} = 160 \text{ cm}^2 \times \frac{1 \text{ m}^2}{10000 \text{ cm}^2}$$ $$A_{min} = 0.016 \text{ m}^2$$

Pressure is defined as force per unit area.

$$P = \frac{F}{A_{min}}$$ $$P = \frac{50 \text{ N}}{0.016 \text{ m}^2}$$ $$P = 3125 \text{ N/m}^2$$ $$P = 3125 \text{ Pa}$$

The greatest possible pressure the block will exert on the ground is $\boxed{\text{3125 Pa}}$.