 Intro to Physics – Matter & Energy Unit #2 Kinematics

Objectives and Learning Targets  Understand the question, “What is Physics?”  Identify and explain several disciplines within the study of physics  Define mass, matter, work, and energy Unit #2 Kinematics

What is Physics?  Book definition has to do with… matter energy interactions But, the real question is “Why?” Examples: Why is the sky blue? Why do objects fall? Unit #2 Kinematics

Matter…  Matter – anything that has mass and takes up space  Think of it as the amount of “stuff” in something  Examples of matter: solids (rocks, metals, etc.), liquids (water, vinegar, etc.), gases (helium, nitrogent, oxygen), plasma (sun, stars) Unit #2 Kinematics

Sample Problem #1 Unit #2 Kinematics

Sample Problem #1 Unit #2 Kinematics

Types of Mass Unit #2 Kinematics Inertial Mass – an objects resistance to being accelerated by a force The more inertial mass, the harder it is to accelerate the object of interest Gravitational Mass – the amount of gravitational force experienced by an object The more gravitational mass, the more gravitational force Both types of mass are generally equal for practical purposes

Energy  Energy – often defined as the ability to do work or make a change in something  What is Work?  Work – the process or capacity to move an object  Both definitions are vague, because energy is often difficult to define Unit #2 Kinematics

Mass-Energy Equivalence  Scientists around the turn of the century proposed a strong relationship between matter and energy  1905 Albert Einstein formulated E=mc 2, which show matter and energy are really one in the same  Led the way to nuclear energy, nuclear weapons, particle colliders, etc. Unit #2 Kinematics

Galileo  developed a systematic method of observing, experimenting, and analyzing…the scientific method  B. no set method – but scientists started to systematically analyze problems, along with keeping detailed records Unit #2 Kinematics