Chapter 27, Problem 56A

The Hydra galaxy is moving away from Earth at $6.0\times {10}^{7}m/s$. What fraction of the speed of light is this?

To determine

To determine the fraction of the speed of light.

Answer to Problem 56A

The fraction is 5.

Explanation of Solution

Given data:

Speed of light (v)= 6×10⁷ m/s.

Formula used:

  $Fraction=\frac{c}{v}$.

Calculation:

The fraction of the speed of light is determined by the ratio of the speed of light in a vacuum to the speed of light through other mediums. Because of the speed of light in a vacuum is the reference value.

We know the speed of light c =3×10⁸m/s.

  $=\frac{3\times {10}^{8}m/s}{6\times {10}^{7}m/s}$ .

= 5.

The fraction of speed of light has no units.

Conclusion:

The fraction of speed of light is 5.