A black hole is an object whose gravitational field is so strong that even light cannot escape from it. To what approximate radius would Earth (mass = `5.98xx10^(24)kg`) have to be compressed to be a black hole?

Options

A. `10^(-9)m`
B. `10^(-6)m`
C. `10^(-2)m`
D. 100m

Answer

C

Explanation

Light cannot escape from a black hole,
`V_(esc)=C`
`sqrt((2GM)/(R))=CorR=(2GM)/(C^2)`
`R=(2xx6.67xx10^(-11)Nm^(2)kg^(-2)xx5.98xx10^(24)kg)/((3xx10^(8)ms^(-1))^(2))`
`=8.86xx10^(-3)m~~10^(-2)m`