Description
Tanusri Gururaj, Academic content writer of Physics at Edumarz
The motion of any object is described using the following terms-
Distance: It is the length of the path covered by an object. It is a scalar quantity and hence, it has magnitude but no direction.
Displacement: It is the shortest distance between the initial and final points. It has both magnitude and direction since it is a vector quantity.
Speed: It is defined as the distance that an object travels per unit of time.
Velocity: It is the distance travelled in a given direction per unit of time.
Acceleration: The measure of how fast the velocity of an object changes.
Time: The duration of any particular event.
Understanding distance and displacement with an example-
Consider this example of a triangular path.
Let us assume that a person goes from path A to B and then from B to C.
The distance is the length of the actual path covered by the person that is AB + BC.
The displacement is the shortest distance between the initial and final points and hence will be AC.
Understanding speed and velocity with an example-
52 km/hr is the speed of a truck ‘A’ on a highway, whereas 52 km/hr east is the velocity of a truck ‘B.’
The explanation behind this is that in the case of truck ‘B,’ 52 km/hr east gives both magnitude and direction, where 52 km/hr is the magnitude and east is the direction.
Formulae related to this concept-
Speed = distance/time
Unit = m/s
Velocity = displacement/time
Unit = m/s
Acceleration = Change in velocity of the object/time taken for the velocity change
Change in velocity = final velocity of object – initial velocity of object
Unit = m/s2
Uniform Motion
The object undergoing uniform motion covers equal distances in equal intervals of time.
For example, a car covers 20m in the first second, the next 20m in the next second, and so on.
Non-uniform motion
In this type of motion, the particular object travels unequal distances in equal intervals of time.
For example, a car covers 1km in the first 35 seconds, 0.9km in the next 35 seconds.