Mechanical Energy Physics Example 1

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Example 1

easy
A 1 kg1 \text{ kg} ball at height 5 m5 \text{ m} moves at 6 m/s6 \text{ m/s}. What is its total mechanical energy? Use g=10 m/s2g = 10 \text{ m/s}^2.

Solution

  1. 1
    KE: 12mv2=12(1)(36)=18 J\frac{1}{2}mv^2 = \frac{1}{2}(1)(36) = 18 \text{ J}.
  2. 2
    PE: mgh=1×10×5=50 Jmgh = 1 \times 10 \times 5 = 50 \text{ J}.
  3. 3
    Total: E=KE+PE=18+50=68 JE = KE + PE = 18 + 50 = 68 \text{ J}

Answer

E=68 JE = 68 \text{ J}
Mechanical energy is the sum of kinetic and potential energy. In the absence of friction and other non-conservative forces, it remains constant.

About Mechanical Energy

The total of kinetic energy and potential energy in a mechanical system at any given moment.

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