Final answer:
The pressure exerted by the water cistern on its base is calculated using the formula Pressure = Force / Area, which results in 40 kPa given the dimensions and volume of the cistern.
Step-by-step explanation:
The question asks us to calculate the pressure exerted by a water cistern on its base. To find this, we use the formula Pressure = Force / Area. The weight of the water (Force) is the product of its volume and density (assuming the density of water is approximately 1000 kg/m³), and the Area is the base of the cistern on which this force acts.
To begin, we need to convert the base measurement from mm to m, which gives us 0.6 m x 1.2 m. Then, the weight of the water can be calculated by multiplying its volume (250 liters or 0.25 m³) with the density of water (1000 kg/m³). We then multiply the result by the acceleration due to gravity (9.81 m/s²) to get the force in newtons.
Next, we calculate the Area (0.6 m x 1.2 m) in square meters. Finally, we divide the Force by the Area to get the pressure in pascals (Pa), which we can then convert into kilopascals (kPa) since 1 kPa = 1000 Pa.
After performing these calculations, we find that the correct answer is option b) 40 kPa.