To what approximate radius would Earth (mass 5.98×10²⁴ kg) have to be compressed for its escape speed to equal the speed of light, forming a black hole?
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To what approximate radius would Earth (mass 5.98×10²⁴ kg) have to be compressed for its escape speed to equal the speed of light, forming a black hole?

G1 Physics · Accepted Answer

Step 1: Set escape speed √(2GM/R) equal to c. This gives Schwarzschild radius R=2GM/c². Step 2: Insert G≈6.67×10⁻¹¹, M≈5.98×10²⁴ and c≈3×10⁸ to obtain R≈8.9×10⁻³ m≈10⁻² m. Final answer: C — 10⁻² m.