Question

What would happen if the sun suddenly became a black hole without changing its mass?

Answer 1

It would shrink to a radius of 2.95 km

Step-by-step explanation:

In order to be a black hole, the Sun must shrink so that its radius becomes equal to its Schwarzschild radius:

`r=(2GM)/(c^2)`

where

G is the gravitational constant

`M=1.99\cdot 10^(30) kg` is the mass of the Sun

c is the speed of light

Substituting into the equation, we find

`r=(2(6.67\cdot 10^(-11)m^3 kg^(-1) s^(-2))(1.99\cdot 10^(30) kg))/((3\cdot 10^8 m/s)^2)=2950 m=2.95 km`

So, the Sun should shrink to a radius of 2.95 km.