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A black hole is an object whose gravitat...

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 compresed to be a black hole?

A

`10^(-9) m`

B

`10^(-6) m`

C

`10^(-2) m`

D

100 m

Text Solution

Verified by Experts

The correct Answer is:
C
Escape velocity `ge c`
`sqrt((2GM)/(r )) ge c`
`r le (2GM)/(c^(2))`
`r le 8.86 xx 10^(-3) m`
Order of magnitude [values `8.88 gt 3.16` (standard)] So, power of 10 for order of magnitude is (-3+1) = -2
so `r le 10^(-2) m`
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