Answer: 90Kg
Step-by-step explanation:
The mass of air hitting the sail each second can be calculated as:
mass of air = density of air * volume of air
The volume of air hitting the sail can be calculated as:
volume of air = area of sail * velocity of wind * time
Here, the area of sail is given as 3.8 m², the velocity of wind is 20 ms^-1, and the time is 1 second (since we want to calculate the mass of air hitting the sail each second).
Therefore,
volume of air = 3.8 m² * 20 ms^-1 * 1 s = 76 m³
Using the given density of air of 1.2 kg m^-3, we can calculate the mass of air hitting the sail each second as:
mass of air = 1.2 kg m^-3 * 76 m³ = 91.2 kg
Therefore, the mass of air hitting the sail each second is approximately 90 kg.