Answer:
(This will depend on the type of fuel, I will assume that the fuel is petrol)
First, let's find the expected energy consumption in the US for the next 10 years.
We know that in one year, a person consumes 3.5*10^11 joules.
There are 310,000,00 people on the US
Then the total consumption in one year is:
310,000,000*3.5*10^11 joules = 1.085*10^20 J
In 10 years the consumption is 10 times the consumption of a single year, then the expected energy consumption in the US for the next 10 years is:
10*1.085*10^20 J = 1.085*10^21 J
Now let's find the mass of fuel required.
We know that a liter of petrol has 31,536,000 joules of energy,
And a liter of petrol weights 0.75 kg
To find the number of liters of petrol that we need, we need to find the quotient between the expected energy consumption in the next 10 years and the energy of a single liter of petrol, this is:
N = (1.085*10^20 J)/(31,536,000 j) = 3.44*10^13
We will need 3.44*10^13 liters of petrol.
And the total mass of petrol will be:
M = 3.44*10^13*0.75 kg = 2.58*10^13 kg of fuel.
