Energy
Energy is the ability to do work. It can be kinetic (motion), potential (position), or other forms. Energy is transferred when work is done.
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What is energy?
Energy is the capacity to do work. The SI unit is the joule (J). Energy can exist in many forms: kinetic energy (due to motion), gravitational potential energy (due to height), elastic potential energy, thermal energy, etc. When work is done, energy is transferred from one form or object to another.
✔ Key takeaway: Energy is the ability to do work; unit is the joule (J).
Kinetic and potential energy
Kinetic energy KE = ½mv² depends on mass and speed. Gravitational potential energy PE = mgh depends on mass, gravitational field strength g, and height h. As an object falls, PE decreases and KE increases.
✔ Key takeaway: KE = ½mv²; PE = mgh. Energy can transform between forms.
Link to simulator: Watch KE and PE change as the object moves along the track.
💭 Think about this:
How is the work done by gravity related to the change in potential energy?