Question

Estimate the mass of the luminous matter in the known universe, given there are 10¹¹ galaxies, each containing 10¹¹ stars of average mass 1.5 times that of our Sun.

(a) 1.5×10⁵³kg
(b) 2.25×10⁵³kg
(c) 3.75×10⁵³kg
(d) 4.5×10⁵³kg

Answer 1

The estimated mass of the luminous matter in the known universe is approximately 1.5 x 10^23 kg.

Step-by-step explanation:

To estimate the mass of the luminous matter in the known universe, we need to calculate the total mass of stars in all the galaxies. Given that each galaxy contains 10^11 stars and each star has an average mass of 1.5 times that of our Sun, we can find the total mass by multiplying the number of galaxies by the number of stars in each galaxy and then multiplying that by the average mass:

Total mass = (10^11 galaxies) * (10^11 stars/galaxy) * (1.5 times the mass of our Sun)

Using this calculation, the estimated mass of the luminous matter in the known universe is approximately 1.5 x 10^23 kg, which is option (a) in the given choices.