Page 119 - SCERT Kerala State Syllabus 8th Standard Basic Science Textbooks English Medium Part 1_Neat

Analyse Table 9.1 and complete it suitably.

Situation State of motion State of rest

A passenger in a moving with respect to the bus

bus with respect to the road
A crow sitting on a cow with respect to the cow

grazing in a field with respect to the ground

A child standing in a with respect to the ground
field. with respect to the sun

A book on a rotating table

Table 9.1

Fig. 9.1
From the analysis of the table, didn’t you understand that we can
state whether an object is in a state of rest or motion only with
reference to another object? The object which is taken as reference
is the reference body.
Reference body is the object with respect to which the state of rest or
motion of an object is described.

If the position of an object changes with respect to the reference
body then the body is said to be in motion. If the position does not
change, the body is said to be at rest.

A body in motion undergoes a change of position. How can we
determine this?
Distance and Displacement

The path through which a person travelled to his office and returned
home are depicted in Fig.9.2. He took the road near the hospital to
go to the office.

118 Basic Science VIII