Answer:
The atmospheric pressure in atm=0.885 atm
Explanation:
Given that
Local pressure (h)= 30 ft of water height ( 1 ft= 0.3048 m)
We know that pressure in given by
P=ρgh
We know that ρ of water is 1000
So pressure
P=1000(9.81)(9.144)
We know that 1000 Pa=0.00986 atm
So P=0.885 atm
The atmospheric pressure in atm=0.885 atm
Answer: Partial pressures are 0.6 MPa for nitrogen gas and 0.4 MPa for carbon dioxide.
Explanation: <u>Dalton's</u> <u>Law</u> <u>of</u> <u>Partial</u> <u>Pressure</u> states when there is a mixture of gases the total pressure is the sum of the pressure of each individual gas:
The proportion of each individual gas in the total pressure is expressed in terms of <u>mole</u> <u>fraction</u>:
= moles of a gas / total number moles of gas
The rigid tank has total pressure of 1MPa.
molar mass = 14g/mol
mass in the tank = 2000g
number of moles in the tank: 
= 142.85mols
molar mass = 44g/mol
mass in the tank = 4000g
number of moles in the tank: 
= 90.91mols
Total number of moles: 142.85 + 90.91 = 233.76 mols
To calculate partial pressure:
For Nitrogen gas:
= 0.6
For Carbon Dioxide:
0.4
Partial pressures for N₂ and CO₂ in a rigid tank are 0.6MPa and 0.4MPa, respectively.
Answer is given below
Explanation:
we know that some common types of throttling devices are
- Hard -throttling devices
- Capillary valve
- Constant pressure throttling devices
- Thermostatic expansion valve
- Float expansion valve
so here throttling devices commonly used in refrigeration and air-conditioning because
- To reduce the coolant pressure, the high pressure of the refrigerant from the condenser is necessary to reduce the evaporation to obtain evaporation at the right temperature
- To meet the refrigerated load, the throttling valve flows through the coolant to cool the load at high temperatures.
Answer:
Accuracy and precision allow us to know how much we can rely on a measuring device readings. ±.001 as a "accuracy" claim is vague because there is no unit next to the figure and the claim fits better to the definition of precision.
Explanation:
Accuracy and Precision: the golden couple.
Accuracy and precision are key elements to define if a measuring device is reliable or not for a specific task. Accuracy determines how close are the readings from the ideal/calculated values. On the other hand, precision refers to repeatability, that is to say how constant the readings of a device are when measuring the same element at different times. One of those two key concepts may not fulfill the criteria for measuring tool to be used on certain engineering projects where lack of accuracy (disntant values from real ones) or precision (not constant readings) may lead to malfunctons and severe delays on the project development.
±.001 what unit?
The manufacturer says that is an accuracy indicator, nevertheless there is now unit stated so this is not useful to see how accurate the device is. Additionally, That notation is more used to refer to device tolerances, that is to say the range of possible values the instrument may show when reading and element. It means it tells us more about the device precision during measurments than actual accuracy. I would recommend the following to the dial calipers manufacturers to better explain its measurement specifications:
- Use ±.001 as a reference for precision. It is important to add the respective unit for that figure.
- Condcut test to define the actual accuracy value an present it using one of the common used units for that: Error percentage or ppm.
