Conservation of Energy

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Energy Noun

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[en-er-jee]

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Energy

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The ability to do work or cause change in a system, existing in various forms like kinetic or potential energy.

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Example: This diagram shows work, which is the transfer of energy. Positive work adds energy to an object, while negative work removes energy from it.

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Kinetic Energy Noun

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[ki-net-ik en-er-jee]

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Kinetic Energy

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The energy an object possesses due to its motion, which is dependent on both its mass and its velocity.

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Example: At the highest point of the roller coaster track, the cart has maximum potential energy and zero kinetic energy because it is momentarily stopped before moving.

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Potential Energy Noun

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[po-ten-shul en-er-jee]

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Potential Energy

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Stored energy an object has based on its position, condition, or chemical composition, ready to be converted into other forms.

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Example: Pushing a boulder up a mountain stores energy due to its increased height; this stored energy is called gravitational potential energy.

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Mechanical Energy Noun

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[muh-kan-i-kuhl en-er-jee]

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Mechanical Energy

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The total energy of an object or system, calculated as the sum of its kinetic energy and its potential energy.

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Example: Mechanical energy is the sum of potential energy (PE) and kinetic energy (KE). At the top of the hill, the cart has maximum PE and zero KE.

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Law of Conservation of Energy Noun

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[law uv kon-ser-vey-shun uv en-er-jee]

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Law of Conservation of Energy

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The fundamental principle stating that energy cannot be created or destroyed, only transformed or transferred from one form to another.

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Example: A cyclist climbing a hill converts motion into stored potential energy. Going downhill, this potential energy converts back into the energy of motion (kinetic energy).

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Energy Transformation Noun

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[en-er-jee trans-for-mey-shun]

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Energy Transformation

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The process of energy changing from one form to another, such as potential energy converting into kinetic energy within a system.

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Example: A generator transforms mechanical energy from the rotating wire coil into electrical energy, which then becomes light and heat energy in the bulb.

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First Law of Thermodynamics Noun

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[furst law uv thur-moh-dahy-nam-iks]

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First Law of Thermodynamics

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The scientific law stating that the total energy of an isolated system remains constant; a restatement of energy conservation.

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Example: This diagram shows that the change in a system's internal energy (ΔU) equals the heat added (ΔQ) minus the work done (W), demonstrating energy conservation.

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Gravitational Potential Energy Noun

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[grav-i-tey-shun-ul po-ten-shul en-er-jee]

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Gravitational Potential Energy

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The potential energy an object has due to its position in a gravitational field, dependent on its mass and height.

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Example: A figure standing at the top of stairs has stored energy (gravitational potential energy) because of its high position relative to the ground.

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Velocity Noun

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[vuh-los-i-tee]

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Velocity

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The rate of change of an object's position with respect to a frame of reference, incorporating both speed and direction.

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Example: This image shows a car moving at a specific speed (20 m.p.h.) in a specific direction (left), which together define its velocity.

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Mass Noun

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[mas]

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Mass

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A measure of the amount of matter in a physical body, which determines its inertia and gravitational attraction to other bodies.

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Example: A balance scale shows that the apple has more mass than the 1-gram weight, causing the scale to tip down on the apple's side.