1. When you inquire about "100mH2O being equal to how many MPa," you are essentially asking for the pressure exerted by a column of water 100 meters in height, expressed in megapascals.2. To calculate this pressure, you can use the formula P = ρgh, where ρ represents the density of water, g is the acceleration due to gravity, and h is the height of the water column.3. Under standard conditions, the density of water ρ is approximately 1000 kg/m3, and the acceleration due to gravity g is roughly 10 m/s2.4. Substituting these values into the formula, you get P = 1000 * 10 * 100 = 1,000,000 Pa.5. 1,000,000 Pa is equivalent to 1 MPa, therefore the pressure exerted by a 100-meter water column is 1 MPa.6. Additionally, 1 MPa can also be represented as 1 * 10^6 Pa or 10^6 mPa.