Answer:
7,217*10^28 atoms/m^3
Explanation:
- Metal: Vanadium
- Density: 6.1 g/cm^3
- Molecuar weight: 50,9 g/mol
The Avogadro's Number, 6,022*10^23, is the number of atoms in one mole of any substance. To calculate the number of atoms in one cubic meter of vanadium we write:
1m^3*(100^3 cm^3/1 m^3)*(6,1 g/1 cm^3)*(1 mol/50,9g)*(6,022*10^23 atoms/1 mol)=7,217*10^28 atoms
Therefore, for vanadium we have 7,217*10^28 atoms/m^3
Answer:
0.5°c
Explanation:
Humidity ratio by mass can be expressed as
the ratio between the actual mass of water vapor present in moist air - to the mass of the dry air
Humidity ratio is normally expressed in kilograms (or pounds) of water vapor per kilogram (or pound) of dry air.
Humidity ratio expressed by mass:
x = mw / ma (1)
where
x = humidity ratio (kgwater/kgdry_air, lbwater/lbdry_air)
mw = mass of water vapor (kg, lb)
ma = mass of dry air (kg, lb)
It can be as:
x = 0.005 (100) / [(100 - 100)]
x = 0.005 x 100 / (100 - 100)
x = 0.005 x 100 / 0
x = 0.5°c
So the temperature to which atmospheric air must be cooled in order to have humidity ratio of 0.005 lb/lb is 0.5°c
Answer:
1200KJ
Explanation:
The heat dissipated in the rotor while coming down from its running speed to zero, is equal to three times its running kinetic energy.
P (rotor-loss) = 3 x K.E
P = 3 x 300 = 900 KJ
After coming to zero, the motor again goes back to running speed of 1175 rpm but in opposite direction. The KE in this case would be;
KE = 300 KJ
Since it is in opposite direction, it will also add up to rotor loss
P ( rotor loss ) = 900 + 300 = 1200 KJ
