pH and Hydronium Concentration

pH

Measure of hydronium ions in a solution

Acids

Substances with pH less than 7 (e.g., lemon)

Bases

Substances with pH more than 7 (e.g., soaps)

Neutral

pH of 7 (e.g., pure water)

Distance

Length of path an object moves along

Displacement

Difference between initial & final position

Constant Speed

Object travels same distance each second

Instantaneous Speed

Speed at a particular instant in time

Acceleration

Rate of change of velocity over time

Force

Push or pull with strength and direction (e.g., gravity)

Weight

Gravitational force exerted on an object

Mass

Amount of matter in an object

Static Friction

Prevents surfaces from sliding past each other

Sliding Friction

Opposes motion of surfaces sliding past each other

Fluid Friction

Friction between a surface and a fluid (e.g., air resistance)

Newton's First Law

Object in motion stays in motion unless acted upon by a force

Newton's Second Law

F = ma; Force equals mass times acceleration

Newton's Third Law

For every action, there is an equal and opposite reaction

Centripetal Force

Force acting perpendicular to motion, towards center of curve

Momentum

Product of mass and velocity of an object

Law of Conservation of Momentum

Total momentum of objects remains constant unless acted upon by external forces

Elastic Collision

Colliding objects bounce off each other

Inelastic Collision

Colliding objects stick together after collision