SPEED, VELOCITY AND ACCELERATION

 

 

UNITS:

 

the metric system or SI (Système International) is used in Canada.

 

Base Units are the units from which the other units are derived.

Length:  metre (m)

Time:  second (s)

Mass:  kilogram (kg)

 

Derived units are the units derived from the base units.  Examples:  m/s, m/s2

 

 

SCALAR QUANTITIES:

 

A scalar quantity is one that has magnitude only.  E.g.:  Speed, distance, time.

 

Distance:  Length of the path travelled and has no direction.  E.g.:  Δd = 16 m

Time:  Time taken.  E.g.:  Δt = 8 s

Speed:  Change in distance divided by the elapsed time.  E.g.:  v = 2 m/s

 

 

 

 

VECTOR QUANTITIES:

 

A vector quantity is one that has both magnitude and direction.  Vector quantities are velocity, position, displacement.

 

Position:  Distance and direction of an object from a reference point. E.g.: d = 8 m [N]

Displacement:  Change in position of an object in a given direction.  :  14 m [S]

Velocity:  E.g.: v = 7m/s [S]

 

 

 

 

UNIFORM ACCELERATION

 

Acceleration is the change in velocity per unit time.

 

 

 

 

vf :  Final velocity.  E.g.: 10 m/s2 [E]

vi :  Initial velocity.  E.g.: 4 m/s2 [E]

Δv:  Change in velocity.  v = 6m/s [E]

Δt:  Time interval.  t = 2 s

 Acceleration.  E.g.: 3 m/s2 [E]