Question

The Sun is orbiting around the entire galaxy such that it completes a full orbit once every 2 × 10 8 years. Using careful measurements of phenomena known as masers, we have acurately measured the distance to the center of the galaxy to be approximately 8 kpc (kiloparsecs). This is enough information to calculate our orbital speed. (Assume that the path the Sun takes is a circle which has a circumference of C = 2 ? R .) Report your answer in kilometers per second.

Answer 1

Answer:

245.75 km/sec

Explanation:

We have given distance as 8 kilo parsec

We know that $1\ kilo\ parsec=3.086\times 10^{16}km$

So 8 kilo parsec =8×3.086×$10^{16}$ km=2.469×$10^{17}$ km

We know that circumference = 2×Π×R

So circumference =2×3.14×2.469×$10^{17}$ = 15.50×$10^{17}$ km

We know that $speed =\frac{distance}{time}$

We have given time =2×$10^8$ year

=2$10^8$×365×24×60×60 sec

So $speed=\frac{15.5\times 10^{17}}{6.30\times 10^{15}}=245.75\ km/sec$