Question

Which law is involved in the act of cleaning a carpet by beating it with a stick?
A. First law of motion
B. Second law of motion
C. Law of conservation of energy
D. Law of conservation of mass

Answer 1

Hint:When an object is at rest or in motion, any change in its original state is resisted by its property which is known as inertia. Here, in the example given in the question, when we beat the carpet with a stick, the carpet starts to move. However, the dust particles resist to change their original state of being at rest.

Complete answer:
We will first discuss the process of cleaning a carpet by beating it with a stick. When we begin to beat a carpet by a stick, a force is applied on the carpet by the stick due to which the carpet begins to move. But, the dust particles present on the carpet initially resist this change in the motion of carpet due to their inertia. Therefore, a backward force is exerted on the dust particles due to forward motion of the carpet. Because of this backward force, the dust particles start to get the motion in the opposite direction. This is how the dust comes out of the carpet when beaten by a stick.

This case seems to be an example of Newton’s first law of motion which is also known as the law of inertia. This law states that “a body remains in the state of rest or uniform motion in a straight line unless and until an external force acts on it”. It means that a body will not start moving until and unless an external force acts on it. Also, once it is set in motion, it will not stop or change its velocity until and unless some force acts upon it once more.

Hence, option A is the right answer.

Note:There are many daily life examples where Newton’s first law of motion or law of inertia is applied. For instance, a runner continues to run for some distance even after finishing the line due to his inertia, a moving object does not stop by itself, a book lying on a table does not move until and unless a force acts upon it.