What is The forms of energy? — Physics

Definition 70.1 Primary & Middle School Physics · Chapter 70 — Forms of Energy and Conversions

The forms of energy, formally presented: kinetic energy — motion’s share, $\frac12 m v^2$ ; potential energy — stored by position or arrangement (the lifted, the stretched, the compressed); thermal energy — the disordered molecular jiggling that temperature measures; chemical energy — stored in matter’s arrangements: food, fuels, batteries; electrical energy — the marching current’s deliverable; radiant energy — carried by light itself, sunshine’s shipping form; and nuclear energy — locked in the atom’s core, the deepest store humans have opened.

Examples

Example 70.3 (The great trade: $E_p$ against $E_k$ )

Drop a ball from height $h$ : as it falls, its account transfers, joule by joule, from potential to kinetic. At the ground, the whole $m g h$ has become $\frac12 m v^2$ — set them equal and the mass cancels:

v = \sqrt{2 g h},

this year’s square root earning its keep. From $20\,\mathrm{m}$ : $v = \sqrt{2 \times 9.8 \times 20} \approx 20\,\mathrm{m}/\mathrm{s}$ — seventy kilometres per hour, mass be what it may. The pendulum plays the trade both ways forever (minus a whisper to the air); the skateboarder in the half-pipe likewise: height to speed to height, the two formulas passing one sum back and forth.

Read in context →

Examples

Related terms