<p> Introduction to Physics</p><p>I. What is Physics? A. Physics is the study of the interaction of matter and energy. B. Isaac Newton is considered the founder of modern physics.</p><p>II. What is a force? A. A force is a push or a pull. Force gives energy to an object, sometimes causing it to start moving, stop moving or change direction. B. Examples of forces are: friction, gravity, and pushing or pulling. C. Two types of Forces: 1. Balanced- forces that cancel each other out. The two opposing forces are equal. Net force=0. Examples: standing, sitting. 2. Unbalanced- put an object in motion. The two opposing forces are not equal. Examples: hitting a tennis ball with a racket, pushing someone out of their chair. III. Acceleration A. The rate of change of velocity (speed with direction) over time. B. Measured in meters per second squared (m/s²).</p><p>IV. Weight vs. Mass A. Weight is a measure of the force of gravity on an object. B. Is your weight the same here as it is in space? Why or why not? No, because of gravity. C. Is your mass the same here as it is in space? Why or why not? Yes, because mass doesn’t change. D. Gravity is the force that pulls objects toward each other. On Earth, acceleration due to gravity=9.8m/s² E. Weight (w)=mass(m) x acceleration due to gravity (g) 1. W=m x g 2. Unit for weight= N(Newton)= 1kg x 1m/s² V. Newton’s Laws A. Newton’s 1st Law 1. Law of Inertia (the tendency of an object to resist change in motion). 2. The law states, “An object at rest will remain at rest and an object that is moving at constant velocity will continue moving at constant velocity unless acted upon by an unbalanced force.” 3. THE MORE MASS, THE MORE INERTIA 4. Examples: seatbelts, more people being added to a wagon as someone tries to pull them VI. Friction A. Friction is the force that acts in the direction opposite to the motion of the moving object. B. Friction will cause a moving object to stop or slow down. C. Examples: pushing a box up an incline, tires on the road</p>