Question

explain in details how the mass of an unknown object can be measured by physical balance??​

Answer 1

Answer:

The physical balance or called as the beam balance was the first instrument which is used to measure the solid mass. It contains a pivoted horizontal lever having the same lengths of the arms. This is called as beam. It has two pans in which the standard weights and the solid substance is to be placed. The unknown mass is placed in the right pan and the standard pans are placed in the left pan, generally. We want to balance the beam so that the beam is completely horizontal. Now calculate the total mass of the standard weights and find out the mass of the unknown substance.

Precautions

i) The weights should be carried with forceps. They should not be carried with bare fingers to avoid the change in its weight due to the presence of moisture and dust particles.

ii) Wet and hot objects should not be kept on the pan.

iii) The beam should be lowered each time before adding or removing weights from the pan.

Answer 2

Answer:

Hello !!✌✌

A physical balance measure mass...

The gravitational force of attraction between the earth and an object depend on the mass of the object.

$f =G \frac{Mm}{ {R}^{2} }$

where G is the universal gravitational constant, M is the mass of the earth, m is the mass of the object and R is the radius of the earth.

For convenience sake, we define a new quantity called acceleration due to gravity which does not depend on the mass of the object (therefore, has the same value for all the objects).

$g = \frac{G}{M} {R}^{2}$

Using the above simplification, we say:

$f = mg$

The beam balance measures the force F exerted by the mass on the beam balance. The beam balance does not directly measure the mass. It uses the fact that the gravitational force on the object is proportional to its mass.