A wrecking ball has a mass of 650 kg. It swings from a cable that is 21 m long. The centripetal force on the ball is 56 N.

Centripetal force is given by F = mv²/r, so solve for speed: v = √(Fr/m). Using F = 56 N, r = 21 m, and m = 650 kg gives v = √(56 × 21 ÷ 650) ≈ 1.35 m/s. The closest choice is A, 1.3 m/s.

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