A person who exercises vigorously several hours a day might take in about 22 m3 of air per day. A tree about 33 m tall and 0.55 m in diameter at its base produces about 84,000 L of oxygen per year. How many people, breathing as described this way, would five such trees supply with oxygen? (Please recall, that 1 m3 = 1000 L, and that normally there's about 20% of oxygen in the air around.)

95 people can breath with five such trees supplying oxygen.

Explanation:

Given data:

a man take in oxygen in a day : 22 (1 = 1000L)

Tree length: 33 m

Tree diameter : 0.55 m

tree produce oxygen in a year : 84,000 L

Tree oxygen in the air : 20%

1 = 1000 L

To find:

number of people can breath with 5 such trees:  ?

Calculation:

Calculate the oxygen produced by 5 trees:

= 5 x 84,000

= 420.000 L

= 420

Calculate the air

= 420 x 100% / 20%

= 2100 m^3

Calculate the number of people:

= 2100 m^3 / 22 m^3

= 95.5

= 95 people

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it is necessary to balance equations in order to get the proper amount of reactants as well as products in order not to make a miscalculation.

you cannot change the subscripts as that would change the substance itself. for instance, diatomic elements such as h2 only have the subscript two when a gas. another example would be so4, if you were to change the subscript, the element would no longer be sulfate.

we change the coefficients instead as that only changes the number of molecules rather than the substance itself.

hope this !