The volume of a sphere formula is $\displaystyle {V}=\frac{{4}}{{3}}\pi{r}^{{3}}$. Where r is the radius. Units must be consistent.

1. If the units for radius are kilometers, what are the units for the volume?
   • m^3
   • cubic meters
   • kilometers
   • meters
   • cubic kilometers
2. Solve this formula for r.
   • $\displaystyle {r}={\sqrt[{{3}}]{{\frac{{4}}{{3}}\frac{{v}}{\pi}}}}$
   • $\displaystyle {r}={\left(\frac{{3}}{{4}}\frac{\pi}{{v}}\right)}^{{3}}$
   • $\displaystyle {r}={\sqrt[{{3}}]{{\frac{{3}}{{4}}\frac{{v}}{\pi}}}}$
   • $\displaystyle {r}={\left(\frac{{3}}{{4}}\frac{{v}}{\pi}\right)}^{{3}}$
3. The Moon has a radius of about 1,738 km. What is the volume of the Moon (in scientific notation, using 3 decimal places in the mantissa)? Preview Question 6 Part 3 of 6   km^3.
4. The volume of the Earth is about $\displaystyle {1.1}\times{10}^{{12}}\ \text{ km}^{{3}}$. What is the radius of the Earth? (assume the Earth is a perfect sphere, which it isn't) (use at least 1 decimal place). Preview Question 6 Part 4 of 6   km.
5. The Earth's radius is Preview Question 6 Part 5 of 6   times the Moon's radius. (use at least 1 decimal place)
6. The Earth's volume is Preview Question 6 Part 6 of 6   times the Moon's volume.