Class 7 Science: The Use of Energy

Flashcards covering vocabulary and core concepts regarding work, power, and the forms and transformation of energy from the Chapter 7 science curriculum.

Work

Scientifically, the phenomenon that occurs when a displacement happens by applying force on an object; it is the multiplication of force and distance passed by the object ($W = F \times d$).

Power

The rate at which work is done; it is calculated by dividing total work by total time.

Energy

The capacity for doing work, which is directly related to work and measured using the same unit.

Joule

The unit of measurement for both Work and Energy.

Mechanical Energy

A special kind of energy related to actions like running, driving a car, moving a brick upward, or using a catapult; it includes both kinetic and static forms.

Kinetic Energy

The working capacity derived from speed or motion, such as the energy of a moving car or a running person.

Static Energy

Energy stored due to a change in the special state or position of an object, such as a brick moved to a height or a catapult pulled back.

Chemical Energy

Energy stored in food, fuel (such as petrol, gas, wood, and coal), and batteries used in torch lights or radios.

Thermal Energy

Energy used for cooking, running motor cars, or trains; it can be obtained by burning fuels or directly from the sun to keep the earth warm.

Magnetic Energy

A form of energy used by magnets to attract ironic substances.

Light Energy

Energy that comes from the sun, fire, or electrical lights, allowing us to see.

Sound Energy

Energy produced from the vibration of substances, such as when speaking, singing, or playing a flute; it is used in telephones, radios, and televisions.

Electrical Energy

A form of energy that runs industries, fans, lights, and trains, and can be transmitted from one place to another via wire.

Atomic Energy

A very powerful energy obtained by breaking the binding force of the inner content of an atom.

Husking-pedal

A tool used for processing paddy where mechanical energy is turned into sound and thermal energy.

Conservation of Energy

The principle that total amount of energy remains constant in the universe; energy cannot be created or destroyed, only transformed from one state to another.