A glass tube is attached to the bottom of a thin iron rod of length 1m. To what height must the glass tubebe filled with mercury so that the centre of mass of the pendulum formed will not rise or all with changes in temperature? (Linear expansivity of glass =9xx10^(-6)K^(-1), that of iron =12x10^(-6)K^(-1) and cubical edxpansivity of mercury =18.2xx10^(-5)K^(-1))

A glass tube is attached to the bottom of a thin iron rod of length 1m

1.	A glass tube is attached to the bottom of a thin iron rod of length 1m. To what height must the glass tubebe filled with mercury so that the centre of mass of the pendulum formed will not rise or all with changes in temperature? (Linear expansivity of glass =9xx10^(-6)K^(-1), that of iron =12x10^(-6)K^(-1) and cubical edxpansivity of mercury =18.2xx10^(-5)K^(-1))
Answer» ANSWER :`0.146m`