Define dynamics?
Dynamics:
The branch of mechanics that deals with the study of the motion of an object
and the cause of its motion is called dynamics.
Define Force.
Force:
A force moves or tends to move stops or tends to stop the motion of a body. The force can also change the direction of motion of a body
F = ma
SI unit of force is newton
Note: A force can also change the shape or size of a body in which it acts.
Define inertia. Experiment to understand inertia?
OR
What is the law of inertia?
Inertia:
The inertia of a body is its property due to which it any change in its state of rest or motion.
Galileo related the inertia of a body with its mass, the greater the mass of a body greater its inertia.
Inertia ∝ mass of the body
Experiment:
Take a glass and cover it with a piece of cardboard. Place a coin on the cardboard. Now kick the card horizontally, with a jerk of your finger.
The coin does not move with the cardboard due to inertia. The coin falls into the glass as the card flicks away.
Experiment:
Cut a strip of paper. Place it on the table. Stack a few coins at one end. Pull out the paper strip under the coins with a jerk.
Coins stacked over remain undisturbed on pulling the paper strip quickly
Coins stacked over remain undisturbed on pulling the paper strip quickly due to inertia.