A circular disc made by iron is rotating about its axis of rotation with a uniform angular speed \(\omega \)
Determine the change in the linear speed of particle at the rim in percentage. The disc of rim is slowly heated from 20^o C to 50^o C keeping the angular speed uniform. Give that coefficient of linear expansion for the material of iron is  \(1.2\times 10^{ -5\quad }\)\(^{0}\)C^-1

A copper cube of mass 200 g slides down on a rough inclined plane having inclination 37^o at a constant speed. If any loss in mechanical energy goes into the copper block as thermal energy. Find the increase in the temperature of the block as it slides down through 60 cm. Given, specific heat of copper is 420 J Kg^-1K^-1 .

A brass wire 1.8 m long at 27^o C is held taut with little tension between two rigid support. If the wire is cooled to a temperature of -39^o C, what is the tension developed in the wire if its diameter is 2mm?

Answer the following.
The triple point of water is a standard fixed point in modern thermometry. Why? What is wrong in talking the melting point of ice and the boiling point of water as standard fixed points (as was originally done in the Celsius scale)?

What is the temperature of the triple point of water on an absolute scale whose unit interval size is equal to that of the fahrenheit scale?

Explain why
an optical pyrometer (for measuring high temperature) calibrated for an ideal black body radiation gives too low a value for the temperature of a red hot iron piece in the open, but gives a correct  value for the temperature when the same piece is in the furnace.

Distinguish between conduction, convection and radiation

A brass rod of length 50cm and diameter 3.0 mm is joined to a steel rod of the same length and diameter. What is the change in length of the combined rod at 250⁰ C, if the original length are at 40.0⁰ C? Is there 'thermalstress' developed at the junction? The ends of rod are free to expand. Coefficientt of linear expansion of brass=2.0x10^-5 0C^-1 and that of steel =1.2x10^-5 0C^-1

The figure shows a large tank of water at a constant temperature f}o and a small vessel containing
a mass 'm' ofwater at an initial temperature f}l « f}c). A metal rod of length L, area of cross section  and thermal conductivity K connects the two vessels, Find the time taken for the temperature of the water in the smaller vessel to become \(\theta\)₂ (\(\theta\)₁< \(\theta\)₂ <\(\theta\)₀ ) Specific heat capacity of water is's' and all other heat capacities are negligible.

A block of wood is floating on water at ooe with a certain volume x above the level of water. The temperature of water is gradually increased from ooe to 8 ⁰C, How does the volume x change with change in temperature ?