chapter 4 dynamics

• Newton's first law states that every object will continue in its state of rest or uniform motion in a straight line unless a resultant force acts on it.
• Inertia is the tendency of an object to resist changes in its velocity, including acceleration from rest or deceleration from motion.
• Newton's second law states that when a resultant force acts on an object, it will cause the object to accelerate in the direction of the force. the product of the mass and acceleration of the object gives the resultant force.
• Newton's third law of motion states that for every action there is an equal and opposite reaction. there are 4 characteristics of forces: action and reaction must be the same type of force, action and reaction are equal in magnitude, action and reaction are opposite in direction, and the forces act on different bodies.
• A normal force is a contact force that opposes compression or extension of an object due to external forces acting upon it. It always acts perpendicularly to the surface of contact between two objects.
• Friction is a contact force that resists relative motion between surfaces in contact with one another.