From John Bazell “In metric, one milliliter of water occupies one cubic centimeter, weighs one gram, and requires one calorie of energy to heat up by one degree centigrade—which is 1 percent of the difference between its freezing point and its boiling point. An amount of hydrogen weighing the same amount has exactly one mole of atoms in it. Whereas in the American system, the answer to ‘How much energy does it take to boil a room-temperature gallon of water?’ is ‘Go fuck yourself,’ because you can’t directly relate any of those quantities.”
I was in a situation similar to this one in real life: having to adjust the salt level in a pool.
In metric:
The pool is 8*4 m long and 2m deep on average, the current salt level is 2g/l and the salt comes in 20kg bags.
How many bags of salts do I need to pour in the pool to adjust the salt level to at least 3g/l ?
Answer:
! The pool contains 8m4m2m= 64m³ or 64000l of water, I need an extra 1g/l of salt per litres so 64000l*1g/l = 64000g or 64 kg. So with 4 bags I’ll have enough salt.
In imperial:
The pool is 20*10ft long and 5ft deep on average, the current salt level is 2000ppm and the salt comes in 40lbs bags.
How many bags of salts do I need to pour in the pool to adjust the salt level to at least 3000ppm?
Answer:
! I’m just gonna drive to the store with my truck to pick up 2 bags at the time and see if it’s enough, no way I’m doing the calculation.
From John Bazell “In metric, one milliliter of water occupies one cubic centimeter, weighs one gram, and requires one calorie of energy to heat up by one degree centigrade—which is 1 percent of the difference between its freezing point and its boiling point. An amount of hydrogen weighing the same amount has exactly one mole of atoms in it. Whereas in the American system, the answer to ‘How much energy does it take to boil a room-temperature gallon of water?’ is ‘Go fuck yourself,’ because you can’t directly relate any of those quantities.”
I was in a situation similar to this one in real life: having to adjust the salt level in a pool.
In metric:
The pool is 8*4 m long and 2m deep on average, the current salt level is 2g/l and the salt comes in 20kg bags.
How many bags of salts do I need to pour in the pool to adjust the salt level to at least 3g/l ?
Answer:
In imperial:
The pool is 20*10ft long and 5ft deep on average, the current salt level is 2000ppm and the salt comes in 40lbs bags.
How many bags of salts do I need to pour in the pool to adjust the salt level to at least 3000ppm?
Answer: