Page 1: Key Measurements in Physics Distance (d): The length of a path between its initial and final positions Scalar quantity SI unit: meters (m) Displacement (Δd): The net change in position of an object Vector quantity SI unit: meters (m) Average speed (s): The rate at which an object changes its location Scalar quantity SI unit: meters per second (m/s) Instantaneous speed: The speed of an object at a specific instant Scalar quantity SI unit: meters per second (m/s) Average velocity (v): The rate of change in position Vector quantity SI unit: meters per second (m/s) Instantaneous velocity: The velocity of an object at a specific instant Vector quantity SI unit: meters per second (m/s) Page 2: Final velocity (vf): The velocity of an object at a specific instant Vector quantity SI unit: meters per second (m/s) Initial velocity (vi): The velocity of an object at the start of its motion Vector quantity SI unit: meters per second (m/s) Acceleration (a): The rate of change in velocity Vector quantity SI unit: meters per second squared (m/s^2) Average acceleration: The rate of change in velocity over a given time interval Vector quantity SI unit: meters per second squared (m/s^2) Instantaneous acceleration: The acceleration of an object at a specific instant in time Vector quantity SI unit: meters per second squared (m/s^2) Weight (Fg): The measure of the force of gravity acting on an object with mass Vector quantity SI unit: Newtons (N) Coefficient of friction (μ): The ratio between the force necessary to move one surface horizontally over another and the pressure between the two surfaces Scalar quantity Page 3: Net force (Fnet): The sum of all the forces acting on an object in a given direction Vector quantity SI unit: Newtons (N) Newton's Second Law of Motion: Every object in the universe attracts every other object with a force that is directly proportional to the product of their masses and inversely proportional to the square of the distance between them Gravitational force (Fg): The force of attraction between every two objects due to their mass Non-contact force SI unit: Newtons (N) Normal force (Fn): The support force created by a surface when a force is applied Contact force SI unit: Newtons (N) Tension force (Ft): The force transmitted through an object when pulled by forces acting from opposite sides Contact force SI unit: Newtons (N) Applied force (Fa): A force which is applied to an object by another object; a push or pull Contact force SI unit: Newtons (N) Friction force (Ff): A force that opposes motion when two surfaces are in contact Contact force SI unit: Newtons (N) Page 4: Work (W): The transfer of energy to an object Scalar quantity SI unit: Joules (J) Power (P): The rate at which energy is transferred; the rate at which work is done Scalar quantity SI unit: Watt (W) Gravitational potential energy (GPE): Energy due to an object's position in a gravitational field Scalar quantity SI unit: Joules (J) Kinetic energy (KE): Energy due to the motion of an object Scalar quantity SI unit: Joules (J) Mechanical energy (ME): The sum of all the energy in an object Scalar quantity SI unit: Joules (J) Page 5: Types of Forces Gravitational force (Fg): The force of attraction between every two objects due to their mass Non-contact force Normal force (Fn): The support force created by a surface when a force is applied Contact force Tension force (Ft): The force transmitted through an object when pulled by forces acting from opposite sides Contact force Applied force (Fa): A force which is applied to an object by another object; a push or pull Contact force Friction force (Ff): A force that opposes motion when two surfaces are in contact