I am measuring the crop water use (ET) by using pots and lettuce crop as plant material, all the data of daily weighted pots are ready but I want to find the surface area of each pot. Can you please help me to find the surface area of a pot with the above-mentioned diameters and height to compute daily evapotranspiration?
I guess your pot has more or less the shape of a conical frustum (i.e. a cone with a cut-off tip). The surface area of a conical frustum without the bottom and top areas is A = pi * (r1 + r2) * s = pi * (r1 + r2) * sqrt((r1 - r2)^2 + h^2), where r1 and r2 are the bigger and smaller radius of the frustum, respectively, s is the slant height (length of the side) and h is the height of the frustum.
You likely want to include the area of the bottom, but not of the opening at the top (because the pot is open there), so you have to add pi * r2^2 and end up with pi * ((r1 + r2) * sqrt((r1 - r2)^2 + h^2) + r2^2) = 3.141593 * ((34.5 / 2 + 32 / 2) * sqrt((34.5 / 2 - 32 / 2)^2 + 32^2 ) + 32^2 / 4) cm^2 = 4149.5 cm^2
Here are the equations for surface and volume of a conical frustum: https://mathworld.wolfram.com/ConicalFrustum.html
I guess your pot has more or less the shape of a conical frustum (i.e. a cone with a cut-off tip). The surface area of a conical frustum without the bottom and top areas is A = pi * (r1 + r2) * s = pi * (r1 + r2) * sqrt((r1 - r2)^2 + h^2), where r1 and r2 are the bigger and smaller radius of the frustum, respectively, s is the slant height (length of the side) and h is the height of the frustum.
You likely want to include the area of the bottom, but not of the opening at the top (because the pot is open there), so you have to add pi * r2^2 and end up with pi * ((r1 + r2) * sqrt((r1 - r2)^2 + h^2) + r2^2) = 3.141593 * ((34.5 / 2 + 32 / 2) * sqrt((34.5 / 2 - 32 / 2)^2 + 32^2 ) + 32^2 / 4) cm^2 = 4149.5 cm^2
Here are the equations for surface and volume of a conical frustum: https://mathworld.wolfram.com/ConicalFrustum.html
You need to weigh the soil you put in those pots, no matter what size or volume they are!! but keep them all same size and same colour and material.
@Jörg: Nope, not really, the evaporation over the soil surface, pot walls and the bottom (which rests on the floor and hence has little contact to the air) will be vastly different. Most likely the largest fraction of water will evaporate over the soil surface. It also matters a great deal whether plastic and clay pots are used... In either case, that's not really what Yasin asked for, and the area is necessary in case it is desired to calculate how much water gets lost over pot walls.
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