Key words

Key words

a)Energy:

Energy is the capacity of a physical system to do work. The common symbol for energy is the uppercase letter E. The standard unit is the joule, symbolized by J. One joule  is the energy resulting from the equivalent of one newton  of force acting over one meter  of displacement. There are two main forms of energy, called potential energy and kinetic energy.

b) Work:

an activity, such as a job, that a person uses physical or mental effort to do, usually for money.

c) Gravity:

Gravity is a force pulling together all matter (which is anything you can physically touch). The more matter, the more gravity, so things that have a lot of matter such as planets and moons and stars pull more strongly.

d) Movement:
change of place or position or posture   a particular instance or manner of moving usually used in plural.

e) Force:

A force is a push or pull upon an object resulting from the object's interaction with another object. Whenever there is aninteraction between two objects, there is a force upon each of the objects. When the interaction ceases, the two objects no longer experience the force. Forces only exist as a result of an interaction.  www.physicsclassroom.com

Source: whatis.techtarget.com                 www.merriam-webster.com      

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