Science of Physics What Is Physics?

Topics of Physics Physics is the study of the physical world Why things do what they do Physics is all around us Explains everyday phenomena Why does it hurt if I slam a door on my hand? Why does it take longer to stop my car on a wet road than a dry road? Why does my book fall to the ground if I drop it? Why is it hotter after a rain than before the rain?

Topics of Physics Seven branches of physics Mechanics – motion and its causes Thermodynamics – heat and temperature Vibrations and Wave Phenomena – specific types of repetitive motion Optics – light Electromagnetism – electricity, magnetism, and light Relativity – particles moving at any speed, including very high speeds Quantum Mechanics – behavior of submicroscopic particles

The Scientific Method Scientific Method – a series of steps used by scientists to solve a problem Make observations and collect data that lead to a question Formulate and objectively test hypotheses by experiments Interpret results, and revise the hypothesis if necessary State conclusions in a form that can be evaluated by others

The Scientific Method Model – a replica or description designed to show the structure or workings of an object, system, or concept Physics uses models to describe only a part reality Cannot describe all aspects of phenomena at the same time System becomes too complex

The Scientific Method System – a set of items or interactions considered a distinct physical entity for the purpose of study Hypothesis – reasonable explanation for observations that can be tested Simplifying the hypothesis can help you focus your experiment on the relevant variables

The Scientific Method Example: Galileo Do heavier objects fall faster than light objects? In 1638, the common belief was that heavy objects fell faster than light objects Galileo challenged this belief with a series of experiments He kept all of the variables the same except weight: size, height, shape

The Scientific Method Controlled experiment – experiment involving manipulation of a single variable or factor The best hypotheses can make predictions in new situations When experiments yield unexpected results, the hypothesis must be revised or abandoned