Inertial Referance Frame
When net force acting on a body is zero, then we can always find frames of reference in which acceleration of the body is zero. Such frames are called inertial reference frames.
A frame moving with constant velocity w.r.t. inertial reference frame is also an inertial reference frame.
Thus in an inertial reference frame, if no net force acts on a body, it's velocity con not change. Let us take an example, A block is kept on the floor, such that net force acting on it is zero, and it is at rest. Frame A moving with constant velocity `10 m//s`.
`text(In the frame A :)` Observer A observes the block, to be moving with same velocity in opposite direction, the velocity of block remains `10 m//s` towards left. Thus the block has zero acceleration w.r.t. A, therefore A is an inertial reference frame.
Inertial frame is an ideal concept because only an isolated object can have zero acceleration. However we can assume earth to be an inertial reference frame, if we neglect its rotation & revolution. This can be done because earth's acceleration due to revolution and rotation is much smaller than the acceleration we notice in daily life i.e acceleration due to gravity (`g = 9.8 m//s^2`).
A frame moving with constant velocity w.r.t. inertial reference frame is also an inertial reference frame.
Thus in an inertial reference frame, if no net force acts on a body, it's velocity con not change. Let us take an example, A block is kept on the floor, such that net force acting on it is zero, and it is at rest. Frame A moving with constant velocity `10 m//s`.
`text(In the frame A :)` Observer A observes the block, to be moving with same velocity in opposite direction, the velocity of block remains `10 m//s` towards left. Thus the block has zero acceleration w.r.t. A, therefore A is an inertial reference frame.
Inertial frame is an ideal concept because only an isolated object can have zero acceleration. However we can assume earth to be an inertial reference frame, if we neglect its rotation & revolution. This can be done because earth's acceleration due to revolution and rotation is much smaller than the acceleration we notice in daily life i.e acceleration due to gravity (`g = 9.8 m//s^2`).
