In general terms how is energy defined

The various forms of energy are classified as kinetic energy, potential energy, or a mixture of them. Kinetic energy is energy of motion, while potential energy is stored energy or energy of position. The total of the sum of the kinetic and potential energy of a system is constant, but energy changes from one form to another. For example, when you hold an apple motionless above the ground, it has potential energy, but no kinetic energy.

When you drop the apple, it has both kinetic and potential energy as it falls. Just before it strikes the ground, it has maximum kinetic energy, but no potential energy. Another broad way of classifying energy is as renewable or non-renewable. Renewable energy is energy that replenishes within a human lifetime. Examples include solar energy, wind energy, and biomass. But a new study finds that water bears propel themselves through sediment and soil on eight stubby legs, in They report Visualizing these smallest Adding Sound to Quantum Simulations Nov.

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