A metre stick is balanced on a knife edge at its centre. When two coins, each of mass 5 g are put one on top of the other at the 12.0 cm mark, the stick is found to be balanced at 45.0 cm. What is the mass of the metre stick?

Open in App

Solution

The mass of the stick is concentrated at 50 cm that is the midpoint of the stick.

Let the mass of the stick be, m

Let the mass of the coin is, 5 g
When one coin is shifted by 12 cm towards point Pthen the second coin is shifted towards centre by 5 cmand the centre of mass gets shifted.

The net torque acting will be conserved for the rotational motion about point R.

10×( 45−12 )g−mg(50−45)=0

m= 330 5 g
Hence the mass is 66 g

Suggest Corrections

Similar questions

Q. A meter stick is balanced on a knife edge at its centre. When two coins each of mass

5 g

are put one on top of the other at

12.0 c m

mark, the stick is found to be balanced at

45.0 c m

. What is the mass of the meter stick?

Q. a meter stick is balanced on a knife edge at its center. when two coins , each of mass 5 g are put one on of the other at the 12 cm mark, the stick is to balanced at 45 cm . the mass of the meter stick is

Q. A metre scale is balanced on a knife-edge at its centre. When a mass of

10

kg is kept at the

12

cm mark, the scale is balanced at

45

cm. What is the mass of the metre scale?

Q. A uniform metre scale balances horizontally on a knife edge placed at

55 c m

mark. When a mass of

25 g

is supported from one end, then the mass of the scale is :

The rock has a mass of 1 kg. What is the mass of the measuring stick if it is balanced by a support force at the one-quarter mark? The centre of mass of the measuring stick is at the one-half mark, one-quarter of the stick's length beyond the pivot.

Join BYJU'S Learning Program