Question 4 • Physics I
Mechanical energy is the sum of gravitational potential energy and kinetic energy. Using g = 9.8 m/s², the potential energy is 2.5 × 9.8 × 18 = 441 J, and the kinetic energy is ½ × 2.5 × 4.5² ≈ 25 J. The total is about 466 J, so the answer is 466 J.
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