A 0.775-m3 rigid tank initially contains air whose density is 1.18 kg/m3. The tank is connected to a high-pressure supply line through a valve. The valve is opened, and air is allowed to enter the tank until the density in the tank rises to 4.95 kg/m3. Determine the mass of air that has entered the tank.

2.9 kg

Explanation:

Given that a 0.775-m3 rigid tank initially contains air whose density is 1.18 kg/m3.

According to the definition of density

Density = mass/volume

1.18 = mass / 0.775

Mass = 1.18 × 0.775

Mass = 0.9145 kg

Given that the tank is connected to a high-pressure supply line through a valve. The valve is opened, and air is allowed to enter the tank until the density in the tank rises to 4.95 kg/m3.

Using the same density formula

Density = mass/volume

4.95 = mass / 0.775

mass = 3.83625 kg

To determine the mass of air that has entered the tank, take away the mass of the air initial in the tank from the mass calculated

Mass = 3.83625 - 0.9145

Mass = 2.923kg

Therefore, the mass of air that has entered the tank is 2.9 kg approximately.

54 degrees incident angle = reflected angle

angle is from normal turned to line of ray