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Examples of Inertia in Motion





Inertia is the natural tendency of an object to resist any change in its motion, which means that it tends to stay at rest or in constant motion along a straight line.
Inertia is a quality of mass and in turn the mass of an object is actually a measurement of its inertia.

Bodies will have different inertia due to their difference of mass. An object with little mass with little inertia will have greater acceleration than an object with larger mass and larger amount of inertia and this will be in response to same net force acting on both. 
As objects have inertia, they resist changing their motion and this leads to applying more forces to things going and change the velocity and ultimately change in acceleration.

The inertia of an object at rest is called static inertia and the one in motion is called dynamic inertia.
Since the inertia of motion is the inability of the body to change its state of motion by itself the examples would also show the same trend.

Some examples of inertia of motion are as follows:

(a)    A person trying to get down from a running bus falls forward.
Explanation: when the person gets down from a running bus the upper part of his body is still in motion and due to this inertia of motion the body topples forward even though he has set his foot on the ground.

(b)    Passengers travelling by train fall forward when the train applies sudden brake
Explanation:  due to inertia of motion the motion of all passengers is equal to the motion of the train and as soon as the brake is applied the passengers feet being in contact with the train floor stops while the upper part falls forward due to inertia of motion.

(c)    Ripe fruits fall from the trees in the direction of wind.
Explanation: the tree sways along with the wind and the inertia of motion makes these fruits sway along with the tree branches. The fruits fall off due to the inertia of motion along the direction of wind.

(d)    The swirling of milk in a glass continues even after the stirring is stopped.
Explanation: a person stirring a spoonful of sugar into a glass of milk finds the milk continuing the swirling movement even after the stirring is stopped and this happens due to the inertia of motion of the milk inside the glass.

(e)    A toy thrown up by a boy inside a moving train moves along with the train
  Explanation: the toy also attains the same velocity as the train inside the train and thus would move along with the train when thrown up. This will apply only when the train is moving with a constant speed or it might fall forward or backward if the speed is altered.