KINEMATICS

1 D MOTION

Frames of reference.

A frame of reference is a set of coordinates that can be used to determine positions and velocities of objects in that frame; different frames of reference move relative to one another.

● It is total path length of a moving particle.

● S I unit is meter

● Displacement is a vector quantity and can be defined by using distance concept.

● It can be defined as distance between the initial point and final point of an object.

● It must be the shortest interval connecting the initial and final points, that is a straight line.

● S I unit is meter.

SPEED

Speed can be defined as “how fast something moves” or it can be explained more scientifically

as “the distance covered in a unit of time”

It is a scalar quantity. We use a symbol v to show speed.

Speed=distance/time

● From the above formula we can say that speed is directly proportional to the

distance and inversely proportional to the time.

● Motor vehicles commonly use kilometer per hour (km/h) as a unit of speed

however in short distances we can use meter per second (m/s) as a unit of speed.

● In my examples and explanations I will use m/s as a unit because it is S I unit of

speed.

VELOCITY

● Velocity can be defined as “speed having direction”. As you can understand from the

definition velocity is a vector quantity having both magnitude and direction.

● We can define velocity as the “rate of change of displacement” whereas “the speed is

rate of change of distance”.

● Average velocity can be defined as total displacement per total time taken.