What is the energy equivalent of an object with a mass of 2 point 5 kilograms ?

Use Einstein’s equation E = mc². With m = 2.5 kg and the speed of light c ≈ 3.0 × 10⁸ m/s, E = 2.5 × (3.0 × 10⁸)² = 2.5 × 9.0 × 10¹⁶ = 2.25 × 10¹⁷ J. Therefore, the energy equivalent is 2.25 × 10¹⁷ J, choice D.

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