How to calculate velocity
Velocity means how fast an object is moving per time in a specified direction. The object changes position as it moves from one point to the other within a time interval in a particular direction. This change in position is called displacement. Therefore, we can describe velocity as how fast an object changes position within an interval of time in a particular direction. Velocity is a vector quantity since it is being described in magnitude and direction. Its unit is in meter per second (m/s) and is expressed as:
Example: A driver left a car park and drove a distance of 50 meters to junction A after 10 seconds. She continued in that direction to a junction B, a distance of 70 meters from the car park. At this point/junction, the driver has spent a total of 15 seconds. Calculate the driver’s velocity from junction A to B.
Calculation:
Note that our positions of interest are just from junction A to junction B; not from the car park. The starting point would be from the park if our interest had been to calculate the velocity between the car park and the final point.
- Starting point distance = starting position (at junction A)= 50m
- Ending point distance = Ending position (at junction B)= 70m
- Initial time (at junction A) = 10seconds
- Final time (at junction B) = 15seconds
Using equation the first equation, we have:
Velocity = (70 - 50)/(15 - 10) = 20/5 = 4m/s in that direction.
Therefore, the driver was mo ving at a velocity of 4m/s from junction A to junction B.
