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Anonymous users2024-01-24After the water tank is filled with water, the cover Q is subjected to the downward pressure of the water (the air below Q is not subject to buoyancy), and the pontoon P is subjected to the buoyancy of the water upward, and only the buoyancy is greater than the pressure, P can pull the Q up and realize automatic flushing.
The deeper the water, the greater the pressure, whereas buoyancy comes from the pressure difference. If the cross-sectional area is the same, the buoyancy cannot be greater than the pressure. Therefore, the cross-sectional area of P should be greater than that of Q.
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Anonymous users2024-01-23Let the height of the pontoon be a, the cross-section of the cover be m, the cross-section of the lid be n, and the short chain length be b, then when the pontoon is completely submerged in the water.
Buoyancy = PGMA, pressure on the lid = PGN (A + B), buoyancy >> pressure.
PGMA >PGN(A+B) (P is the water density and G is the acceleration due to gravity) to cancel PG
ma>(a+b)n
When m<=n the above equation never holds, so the cross-sectional area of the pontoon P should be greater than the cross-sectional area of the cover Q.
When m>n.
m/n>1+b/a
a>nb/(m-n)
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Anonymous users2024-01-22Problem solving ideas and methods].
This is a comprehensive problem that uses pressure, buoyancy and other knowledge to solve practical problems, involving many physical formulas and physical processes. For such problems, students should not be in a hurry to solve them, but first analyze the physical process according to the required quantities and known quantities, form solutions to the problems, and then make specific calculations.
Analysis method: the depth of water in the tank is required, according to Figure 21, the length of the thin wire is known, the thickness of the valve C, and the depth of the pontoon B in the water is known again. The depth of pontoon B in the water is determined by the force it is subjected to.
Perform a force analysis on the buoy B: subject to the upward buoyancy force, the downward gravity, the downward pull force of the valve on it. Because B is stationary, there is:
F float = GB+ F pull, according to Archimedes' principle, F float contains the volume of B in the water, that is, the depth in the water, but the size of F pull is not known.
Perform a force analysis on valve C: subject to upward tension and downward pressure. Because C is at rest, there is: F pull = F pressure.
The tensile force of C is equal to the tensile force of C to B, and F pressure = PSC , P = (h+l)g
At this point, the students can see that the depth of B in the water can be found by using F float = GB+ F pull, and then the depth of the water in the tank.
Reference answer] Let the depth of float B immersed in water be h when valve C is just opened.
F float = GB+F pull.
F-pull = F-pressure.
Because F-pull = F-pull.
So F float = GB + F pressure.
Water gSBh = mBg + water gSC (h + l).
Bring in the data to solve: h = 30cm
Then the water depth is: H=h+ l+d
30cm+10cm+
Then find a professional master to repair or replace the old with a new one!!
<> full of Sun Li's scattered words, please then rotten rough -v-
Generally, if you like this, you must have to complain to the urban construction, and generally the kind of people who clean or manage public toilets are all people who are in pieces, and you can complain there.
The source of the smell of urine is ammonia, and the air in public toilets is full of this gas, and the urine molecule you are talking about should be urea, which is usually not present in the air.
It is the same as the main component of stone, which is calcium carbonate.