Question

The earth weights 5.972×1024
kilograms. A penny weighs 3.1×10−3
kilograms. Approximately how many pennies weigh as much as the earth?

Give your answer in scientific notation using only whole numbers.

x 10

Answer 1

To find out how many pennies weigh as much as the Earth, we can divide the weight of the Earth by the weight of a penny.

Given:
- Weight of the Earth = \( 5.972 \times 10^{24} \) kg
- Weight of a penny = \( 3.1 \times 10^{-3} \) kg

Now, we can perform the following calculation:

\[
\text{Number of pennies} = \frac{\text{Weight of the Earth}}{\text{Weight of a penny}} = \frac{5.972 \times 10^{24}}{3.1 \times 10^{-3}}
\]

To simplify this calculation, we can divide the coefficients and subtract the exponents:

\[
\text{Number of pennies} = \frac{5.972}{3.1} \times 10^{24 - (-3)} = \frac{5.972}{3.1} \times 10^{24 + 3} = \frac{5.972}{3.1} \times 10^{27}
\]

Now we calculate the coefficient \( \frac{5.972}{3.1} \):

\[
\frac{5.972}{3.1} \approx 1.925
\]

Now, rounding this to a whole number gives us approximately 2, so we can write:

\[
\text{Number of pennies} \approx 2 \times 10^{27}
\]

Thus, the answer in scientific notation is:

\[
\boxed{2 \times 10^{27}}
\]