Question

The Milky Way has a radius of approximately 50,000 light years. The visible universe has a size of approximately 15 billion light years. If the Milky Way is represented by an 8 centimeter wide coffee cup , how big would the rest of the universe be in kilometers?

Answer 1

Answer:

24 kilometers

Step-by-step explanation:

It's a simple calculation using cross multiplication:

We have the following ratios:

$\frac{8}{x} = \frac{50,000}{15,000,000,000} \\\\x * 50,000 = 8 * 15,000,000,000\\\\x = 2,400,000$

That's 2.4 million of cm... or 24 000 meters... or 24 kilometers.

That's equivalent to 300,000 cups placed side by side.  That's a long way!

Answer 2

Answer: 12 km

Step-by-step explanation:

The width of the coffee cup is 8 cm. This is the diameter of the coffee cup. You need to calculate the radius of the coffee cup with this formula:

$r=\frac{d}{2}$

Where "d" is the diameter.

Sybstitutiing, you get:

$r=\frac{8cm}{2}\\\\r=4cm$

Therefore, now you know that 4 cm represents the  radius of Milky Way (approximately 50,000 light years), then the rest of the universe in centimeters is represented with:

$x=\frac{(15,000,000,000\ light\ years)(4cm)}{(50,000\ light\ years)}=1,200,000cm$

From cm to km:

$x=(1,200,000cm)(\frac{1km}{100,000cm})=12km$