Question

Explain the meaning of the following statement $1kgf = 9.8N$

Answer 1

Hint: In order to give a suitable reason for the given question, we need to know the relation between the Gravitational metric system and SI unit system of measurements. After that we need to compare both the quantities. Then we can finally conclude with the correct explanation of the given question.

Complete answer:
$1kgf$ or one kilogram force is defined as the force with which the earth pulls an object of mass 1 kg towards itself.
Also, we know that the unit of force in the SI system of measurement is Newton and is represented by $N$.
We know that force is the product of mass and acceleration of a body. Here, in this case for the force due to gravity, the acceleration due to gravity would be acting.
So, we can write,
$F = ma = mg$
$ \Rightarrow 1kgf = 1kg \times g$
$\therefore 1kgf = gN$ …………. (i)
We know that the value of acceleration due to gravity is given by, $g = 9.8m{s^{ - 2}}$.
So, putting the value of $g$ in equation (i), we get,
$1kgf = 9.8N$

Therefore, we can write $1kgf = 9.8N$.

Note: We should also know the fact that the kilogram force or $kgf$ is a metric unit of force and is equal to the product of one kilogram of mass of a body and the acceleration due to gravity on Earth. On the other hand ‘Newton’ is the unit of force in the International System of units or “SI” units. One Newton is defined as the force required in providing an acceleration of one meter per Second Square to a mass of one kilogram of a body.