A non-inertial frame of reference is one that is accelerating and does not obey Newton's first law of motion. Examples given include a car that suddenly stops or changes speed, and the earth, which is rotating and revolving. In a non-inertial frame, a freely moving object will appear to be accelerating even if no external forces act on it, because the observer is also accelerating in the frame of reference. The tides are explained using a non-inertial frame - the earth accelerates relative to inertial space due to gravitational forces from the moon, appearing to cause pseudo forces responsible for tidal effects.

1. Non Inertial Frame Of
Reference

2. Frame Of Reference
The axis or a point from where we observe and
take measurement is called frame of reference
or frame of reference is any co ordinate system
relative to which measurements are taken for
example if experiment is performed in a class
room then our class room is s a frame of
reference , is same experiment is performed in
a train then train is a frame of reference.

3. Types of frames of reference
Obey law of
inertia
Inertial
Non
Inertial
Don’t obey
law of inertia

4. An accelerated frame of reference is of a frame
of reference which do not hold Newton 1st law
or don’t obey law of inertia is known as non
inertial frame of reference.
• For example when a moving car suddenly
stops object inside it don’t remain at rest.
• Earth is rotating and revolving hence strictly
speaking earth is not a inertial frame of
reference.

5. • Suppose you are in an accelerating car looking
at a freely moving object(i.e one with no
force acting on it) you will see that its velocity
is changing because you are in a car which
have acceleration. So in acceleration frame of
reference Newton 1st law doesn’t hold and is
considered as non inertial frame of reference.

6. • It deals with the both inertial and non inertial
frame of reference.
• Einstein said that if body is in non inertial
frame and moving with speed of light then its
time and mass will be infinity and will be
greater than the observed time and mass and
its length contradiction will be smaller than
the observed length.

8. The Tides
What causes the tides? You may know that it has
something to do with the Sun and Moon, and in fact, both
have a contribution. To simplify matters, however, we can
consider only the effect of the Moon and ignore the Sun.
You may think it plausible that the Moon attracts the
water on the side nearest the Moon, so that the situation
is like this:
non-inertial reference frame is used for the
explanation, the pseudo force of inertia, which is
responsible (together with gravitational forces) for
the origin of tides on the earth, is caused by the
translational acceleration of the earth relative to
the inertial space.

9. Imagine that you are travelling on a bus with a
ball beside you on the floor. The bus is moving
forward with a constant velocity of 20km/h.
Bus is moving at 20km/h.
• First of all the ball on the floor does not move,
this is because no net force is acting on it and
Newton law says that a body continues to
maintain its motion until an external force is
applied on it.

10. • When the breaks are applied to the bus it
decelerates , and the ball start to accelerate
toward the front of the bus.
• Now we can see that no external force is
applied to the ball then why the acceleration
is produce in ball.

11. • When the breaks are applied to the bus, the
bus undergoes deceleration or a negative
acceleration, at this moment the acceleration
is produced in a ball without any applied force
and at that moment it become non inertial
frame of reference
• So it is proved that non inertial frame of
reference does not obey Newton’s first law or
law of inertia.

12. .
THANK YOU