A black hole is an object whose gravitational fields is so strong that even light cannot escape from it. To what approximate radius would earth (mass = 5.98 × 10²⁴ kg) have to be compressed to be a black hole?

10^-2 m

Escape velocity : v = \(\sqrt{\frac{2GM}{R}}\)

c= speed of light

c= \(\sqrt{\frac{2GM}{R}}\)

squaring both sides

R = \(\frac{2GM}{c^2}\) = \(\frac{2×6.6×10^{-11}×5.98×10^{24}}{(3×10^8)^2}\)

   = 10^-2m