Normally, the water pressure inside a pump is higher than the vapor pressure: in this case, at the interface between the liquid and the vapor, molecules from the liquid escapes into vapour form. Instead, when the pressure of the water becomes lower than the vapour pressure, molecules of vapour can go inside the water forming bubbles: this phenomenon is called
cavitation.
So, cavitation occurs when the pressure of the water becomes lower than the vapour pressure. In our problem, vapour pressure at
is 1.706 kPa. Therefore, the lowest pressure that can exist in the pump without cavitation, at this temperature, is exactly this value: 1.706 kPa.
Explanation:
Watts are defined as 1 Watt = 1 Joule per second (1W = 1 J/s)
which means that 1 kW = 1000 J/s. A Watt is the amount of energy (in Joules) that an electrical device (such as a light) is burning per second that it's running.
Answer:
Solar cell generates DC
Windmill generates AC
Explanation:
Solar cell generates DC from the panel, to use this DC for electricity it has to be passed to an inverter which convert DC to AC.
Windmill generates AC from the wind blades. This type of energy can be used directly with household appliances using AC, or passed to a rectifier to convert it to DC.
Answer:
Distance: 75 km
Displacement: 45 km
Explanation:
- Distance is a scalar quantity that refers to the total space covered by an object. It is calculated as the sum of the distances covered in each motion, regardless of their direction. therefore in this case:
distance = 60 km + 15 km = 75 km
- Displacement is a vector quantity whose magnitude is equal to the difference between the final point and the starting point of the motion, so it also takes into account the direction of each motion. In this case, the truck moves 60 km east, and then 15 km west: if we call '0' the starting point, the final point will be then
And so the displacement is
Answer:
The work done by the steam is 213 kJ.
Explanation:
Given that,
Mass = 5 kg
Pressure = 150 kPa
Temperature = 200°C
We need to calculate the specific volume
Using formula of work done
Where,R = gas constant
T = temperature
P = pressure
=Atmosphere pressure
m = mass
Put the value into the formula
Hence, The work done by the steam is 213 kJ.
