Answer:
3) the pressure drop across high MERV filters is significant.
Explanation:
MERV (Minimum-Efficiency Reporting Value) is used to measure the efficiency of filter to remove particles. A filter of high MERV can filter smaller particles but this causes an increase in reduced air flow that is an increase in pressure drop. High MERV filters capture more particles causing them to get congested faster and thereby increasing pressure drop.
Excessive pressure drop can cause overheating and lead to damage of the filter. The pressure drop can be reduced by increasing the surface area of the filter.
Answer:
The pressure difference across hatch of the submarine is 3217.68 kpa.
Explanation:
Gauge pressure is the pressure above the atmospheric pressure. If we consider gauge pressure for finding pressure differential then no need to consider atmospheric pressure as they will cancel out. According to hydrostatic law, pressure varies in the z direction only.
Given:
Height of the hatch is 320 m
Surface gravity of the sea water is 1.025.
Density of water 1000 kg/m³.
Calculation:
Step1
Density of sea water is calculated as follows:

Here, density of sea water is
, surface gravity is S.G and density of water is
.
Substitute all the values in the above equation as follows:


kg/m³.
Step2
Difference in pressure is calculated as follows:


pa.
Or

kpa.
Thus, the pressure difference across hatch of the submarine is 3217.68 kpa.
Answer:
"Biofuels"
Explanation:
I don't know if this counts but I guess it's not one of those.
The magnetic force on a free moving charge is perpendicular to both the velocity of the charge and the magnetic field with direction given by the right hand rule. The force is given by the charge times the vector product of velocity and magnetic field.
Answer:
Changing oil.
Explanation:
You need to regularly check and change your car’s oil to ensure smooth running of the vehicle and to prolong the lifespan of its engine.