Questions

No work done as there is no external external pressure in free expansion. 

Hence, Work done in a free expansion process is Zero.

Application of temperature changes in the atmosphere is in adiabatics, or temperature change which are caused by compressing or allowing air to expand.

Usain Bolt is branded as "Fast Man on Earth".

Gravitational Force

Chemical weathering is what happens when rocks are broken down and chemically altered.

Chemical weathering is the breakdown of rocks by chemical reactions. Chemical weathering involves changes in the chemical composition of the existing rock to form new rock. Some examples of chemical weathering are hydrolysis, oxidation, carbonation, dissolution, etc.

Ashok Gehlot is the new Chief Minister of Rajasthan and Sachin Pilot is his Deputy.

Conduction is the movement of heat through a substance by the collision of molecules. It occurs when two object at different temperatures are in contact with each other. Heat flows from the warmer to the cooler object until they are both at the same temperature.