What is Physics?

W HAT IS S CIENCE ? Science is knowledge applied to the natural environment through careful observation. Science is trying to explain the world around us Science is a way of thinking Science is a system of knowledge based on facts or principles The word science was taken from the Latin word “scientia” meaning “to know”

A S CIENTIST : Finds answers through research and experimentation. Confirms results by repeating experiments Learns more by designing and conducting new experiments

Mythbusters use science on every episode…they develop a hypothesis, and then test that hypothesis by performing an experiment

W HAT IS P HYSICS ? Physics is the Branch of Science which studies physical objects (matter) and their behavior (energy) in the universe. Physics uses mathematical relations to explain and predict natural phenomenon. Principles and laws of physics can be expressed as mathematical equations. The acceleration of an object depends on its mass and the force applied to it Newton’s 2 nd Law a=F/m The acceleration of an object depends on its mass and the force applied to it Newton’s 2 nd Law a=F/m Physics is considered by many to be the “central science”

E ARLY P HYSICISTS Galileo Galilei developed many ideas on mechanics, optics, and wave phenomena using what is now known as the Scientific Method of Inquiry. The Book of nature is written in mathematical characters Galileo Galilei

E ARLY P HYSICISTS Sir Isaac described -universal gravitation and the three laws of motion, -laying the groundwork for classical mechanics, -principles of conservation of momentum and angular momentum -He also studied the speed of sound -and proposed a theory of the origin of stars

A LL S CIENTISTS M UST :  Study problems in an organized manner  Make an educated guess as to why things happen  Test their ideas through experimentation  Collect Data  Analyze Results  Draw a Conclusion

T ESTING A H YPOTHESIS Experiments often generate more observations Analyzing data allows us to draw conclusions about the hypothesis The hypothesis can be modified or discarded if it is not supported by experimental evidence.

S CIENTIFIC T HEORY A reasoned explanation tested by many observations and experiments Tells why things are, explains how or why something occurs Three things Must explain clearly and simply Must be repeatable Must be able to make predictions Theories can be changed or modified by new evidence

I T ’ S THE L AW When the theory is used to predict new phenomenon then it may, overtime, become what is called a Scientific Law. (Describes Relationships.)

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