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Kinetic Energy - IB Physics Definition

Reviewed by: Ann Howell

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In IB Physics, kinetic energy (E subscript k) is the energy an object has due to its translational motion (i.e. because it's moving). The faster an object is moving, the greater its kinetic energy.

Kinetic energy can be calculated using the following equation:

E subscript k space end subscript space equals space 1 half m v squared

Where:

  • E subscript k= kinetic energy, measured in joules (straight J)

  • m = mass, measured in kilograms (kg)

  • v = speed, measured in metres per second (straight m space straight s to the power of negative 1 end exponent)

Illustration of a blue car emitting exhaust, labelled "MASS, m," with an arrow indicating direction and "SPEED, V" above it, symbolising motion.
Kinetic energy: The energy an object has when it is moving.

When an object is falling, it is gaining kinetic energy since it is accelerating under gravity. This energy is transferred from the gravitational potential energy it is losing. An object will maintain kinetic energy unless its speed or mass changes.

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Ann Howell

Reviewer: Ann Howell

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Ann obtained her Maths and Physics degree from the University of Bath before completing her PGCE in Science and Maths teaching. She spent ten years teaching Maths and Physics to wonderful students from all around the world whilst living in China, Ethiopia and Nepal. Now based in beautiful Devon she is thrilled to be creating awesome Physics resources to make Physics more accessible and understandable for all students, no matter their schooling or background.

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