Question

If we use 1 millimeter to represent 1 light-year, how large in diameter is the Milky Way Galaxy?
a.100 millimeters
b.100 kilometers
c.1 kilometer
d.100 meters
e.1 million millimeters

Answer 1

Answer:

d.100 meters

Explanation:

The diameter of the Milky Way Galaxy is approximately 100,000 light years.

Here we are using 1 millimiter (1 mm) to represent 1 light-year (1 ly). So, we can set the following proportion:

$1 mm : 1 ly = x : 100,000 ly$

and by finding x, we find the diameter of the Milky Way Galaxy in the scale used:

$x=\frac{(1mm )(100,000 ly)}{1 ly}=100,000 mm = 100 m$

so the correct answer is

d. 100 meters