Water evaporates at the rate of two liters per hour per one square meter of surface. How long will it take to evaporate 30 liters of water from a swimming pool full of water with vertical walls and a flat bottom that holds 56 cubic meters of water?
1. The depth of the pool is 2 meters
2. The pool is circular with a radius of 3 meters
water
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The rate of evaporation = 2 liters per hour per sq. meterjainrahul1985 wrote:Water evaporates at the rate of two liters per hour per one square meter of surface. How long will it take to evaporate 30 liters of water from a swimming pool full of water with vertical walls and a flat bottom that holds 56 cubic meters of water?
1. The depth of the pool is 2 meters
2. The pool is circular with a radius of 3 meters
volume of water in the swimming pool = 56 m^3
Time to evaporate 30 liters of water from the swimming pool = ?
We need to find the surface area of the swimming pool to find this time.
Statement 1:
The depth of the pool is 2 meters
The surface area of the pool = volume / depth = 56/2 -- Sufficient
Statement 2:
The pool is circular with a radius of 3 meters
The surface area = pi*3*3 --- Sufficient
Hence, D
Thanks
Anshu
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Anshu
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Thanks a ton for replying , but I am not sure what formulas have you used here .anshumishra wrote:The rate of evaporation = 2 liters per hour per sq. meterjainrahul1985 wrote:Water evaporates at the rate of two liters per hour per one square meter of surface. How long will it take to evaporate 30 liters of water from a swimming pool full of water with vertical walls and a flat bottom that holds 56 cubic meters of water?
1. The depth of the pool is 2 meters
2. The pool is circular with a radius of 3 meters
volume of water in the swimming pool = 56 m^3
Time to evaporate 30 liters of water from the swimming pool = ?
We need to find the surface area of the swimming pool to find this time.
Statement 1:
The depth of the pool is 2 meters
The surface area of the pool = volume / depth = 56/2 -- Sufficient
Statement 2:
The pool is circular with a radius of 3 meters
The surface area = pi*3*3 --- Sufficient
Hence, D
For statement 2 why didn't you use : Surface Area of a Cylinder = 2 pi r^2 + 2 pi r h
Also I didn't get the formula used in Statement 1 .
Please help me understand .
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Area covered : Pi r^2 + pi *r * h + Pi *r * h
St 1:
We are not sure whether it's a cuboid or a cylindrical structure
Insufficient
St 2 :
Radius is given ,volume is given . So we can find height. And thereby we can find the covered surface area.
Sufficient.
IMO B.
St 1:
We are not sure whether it's a cuboid or a cylindrical structure
Insufficient
St 2 :
Radius is given ,volume is given . So we can find height. And thereby we can find the covered surface area.
Sufficient.
IMO B.
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Then in that case, one needs to assume the given swimming pool is cylindrical only.jainrahul1985 wrote:OA D
Wish experts reply for this one...
but these days, geometrical questions has changed way beyond common mensurations stuff!!
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Formula used :jainrahul1985 wrote: Thanks a ton for replying , but I am not sure what formulas have you used here .
For statement 2 why didn't you use : Surface Area of a Cylinder = 2 pi r^2 + 2 pi r h
Volume = area of the base * height
(So, even if you have the shape of base such as square, triangle, circular, or ploygon, this would work).
In fact using this formula, I can derived the volume of a cylindrical pond as = area of the base * height = (pi*r^2) * h -- which you already know as right.
Same formula : area of the base = volume/ depth.Also I didn't get the formula used in Statement 1 .
Thanks
Anshu
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Anshu
(Every mistake is a lesson learned )
- anshumishra
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The pond (lets say for now), is open. The area 2 pi r^2 + 2 pi r h is the area of the two circular faces (say the top and the bottom part = 2*pi*r^2) and the surface of the sides (2*pi*r*h). We are not interested in that area.jainrahul1985 wrote: For statement 2 why didn't you use : Surface Area of a Cylinder = 2 pi r^2 + 2 pi r h
The water is evaporated because the lower surface is warm, hence the only area we are concerned is the circular area of the bottom of the cylindrical pond = pi*r^2
Hope that helps !
Thanks
Anshu
(Every mistake is a lesson learned )
Anshu
(Every mistake is a lesson learned )