To find the total energy generated by the Sun in a year, you can multiply the energy generated per second by the number of seconds in a year.
Given:
- Energy generated per second by the Sun \( = 4 \times 10^{26} \) joules
- Seconds in a year \( = 3.5 \times 10^{7} \)
Now, calculate the total energy generated in a year:
\[ \text{Total Energy} = (\text{Energy per second}) \times (\text{Seconds in a year}) \]
Substituting the values:
\[ \text{Total Energy} = (4 \times 10^{26}) \times (3.5 \times 10^{7}) \]
Now, multiply the coefficients and the powers of ten separately:
-
Multiply the coefficients: \[ 4 \times 3.5 = 14 \]
-
Add the exponents for the powers of ten: \[ 10^{26} \times 10^{7} = 10^{(26 + 7)} = 10^{33} \]
Putting it all together, we have: \[ \text{Total Energy} = 14 \times 10^{33} \]
To express this in proper scientific notation, we need to adjust the coefficient (14) to be between 1 and 10:
\[ 14 = 1.4 \times 10^{1} \] Thus, \[ 14 \times 10^{33} = 1.4 \times 10^{1} \times 10^{33} = 1.4 \times 10^{34} \]
Therefore, the total energy generated by the Sun in a year, expressed in scientific notation, is:
\[ \boxed{1.4 \times 10^{34}} \text{ joules} \]