$A$ mass of $2\, kg$ is suspended from a rigid support by a thread $AB$. Another thread $CD$ of the same type is attached to the lower end of the $2\, kg$ mass. If the lower thread $CD$ is pulled with a sudden jerk,what happens?

$A$ reference frame attached to the Earth cannot be an inertial frame because

For ordinary terrestrial experiments,the observer in an inertial frame in the following cases is

$A$ particle is moving with a constant speed along a straight line path. $A$ force is not required to

Given below are two statements: one is labelled as Assertion $A$ and the other is labelled as Reason $R.$
Assertion $A:$ An electric fan continues to rotate for some time after the current is switched off.
Reason $R:$ The fan continues to rotate due to inertia of motion.
In the light of the above statements,choose the most appropriate answer from the options given below.

Write and explain Newton's first law of motion.