Question

The distances in space are measured in light-years. The distance from Earth to a star is 5.9 × 10^13 kilometers. What is the distance, in light-years, from Earth to the star (1 light-year = 9.46 × 10^12 kilometers)?

1.61 light-years
3.56 light-years
5.58 light-years
6.23 light-years

Answer 1

you are converting one unit to another unit
we have 1ly=9.45x10^12 km
so we have you need to do:
\[5.9 \times 10^{13} km \cdot \frac{1 ly}{9.46 \times 10^{12} km}\]
that second fraction there is like multiplying by 1 since 1ly=9.45x10^12km

Answer 2

my anyways you will see the km measurements cancel

Answer 3

so you just need to divide the 5.9x10^13 by 9.46x10^12 to get the ly amount

Answer 4

^^
The distance from Earth to a star is
\(\large\tt \begin{align} \color{black}{5.9 × 10^{13} ~~kilometers\\~\\
=5.9 × 10^{13} ~~kilometers\\~\\
= \dfrac{5.9 × 10^{13}}{9.46 × 10^{12}}~~light-years}\end{align}\)

Answer 5

should i divide 5.9 and 9.46??

Answer 6

yes also the exponent parts

Answer 7

\[\frac{5.9}{9.45} \cdot \frac{10^{13}}{10^{12}} ly\]

Answer 8

i got D??

Answer 9

\(\large\tt \begin{align} \color{black}{\checkmark}\end{align}\)

Answer 10

thank you both SO much!