To find out how much energy the Sun generates in a year, you can multiply the energy it generates per second by the number of seconds in a year.
The energy generated by the Sun every second is \(4 \times 10^{26}\) joules, and the number of seconds in a year is approximately \(3.15 \times 10^{7}\).
So, you calculate:
\[ \text{Energy in a year} = \text{Energy per second} \times \text{Seconds in a year} \]
\[ \text{Energy in a year} = (4 \times 10^{26} , \text{J/s}) \times (3.15 \times 10^{7} , \text{s}) \]
To multiply these two numbers in scientific notation:
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Multiply the coefficients (the numbers in front): \[ 4 \times 3.15 = 12.6 \]
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Add the exponents: \[ 10^{26} \times 10^{7} = 10^{(26 + 7)} = 10^{33} \]
So, the combined result before converting to proper scientific notation is:
\[ 12.6 \times 10^{33} \]
Now, we need to rewrite \(12.6\) in proper scientific notation. Since \(12.6\) can be expressed as \(1.26 \times 10^{1}\), we can write it as:
\[ 12.6 \times 10^{33} = 1.26 \times 10^{1} \times 10^{33} = 1.26 \times 10^{34} \]
Thus, the total energy generated by the Sun in a year, in scientific notation, is approximately:
\[ \boxed{1.26 \times 10^{34}} \text{ joules} \]