average speed S.I. units average velocity N.B. very different values for the average speed and average velocity. Often the same symbol is used for speed and velocity. You always need to state whether the symbol represents the speed or velocity. Our tram speeds up continually until it reaches the Origin, it then slows down and stops at the right end of the track. In the return journey, it continually speeds up until it reaches the Origin it then slows down and stops at the left end of the track. The speed and velocity are always changing. Hence, it is more useful to talk around instantaneous values rather than average values. The instantaneous velocity is a vector quantity whose magnitude is equal to the instantaneous speed and who instantaneous direction is in the same sense to that in which the particle is moving at that instant. The velocity vector is always tangential to the trajectory of the particle at that instant. Remember, speed and velocity are
average speed S.I. units average velocity N.B. very different values for the average speed and average velocity. Often the same symbol is used for speed and velocity. You always need to state whether the symbol represents the speed or velocity. Our tram speeds up continually until it reaches the Origin, it then slows down and stops at the right end of the track. In the return journey, it continually speeds up until it reaches the Origin it then slows down and stops at the left end of the track. The speed and velocity are always changing. Hence, it is more useful to talk around instantaneous values rather than average values. The instantaneous velocity is a vector quantity whose magnitude is equal to the instantaneous speed and who instantaneous direction is in the same sense to that in which the particle is moving at that instant. The velocity vector is always tangential to the trajectory of the particle at that instant. Remember, speed and velocity are