If we imagine ideally smooth surfaces and it they are kept in contact, the frictional force acting between them is .

If we imagine two ideally smooth surfaces & if they are kept in contact, the frictional force acting between them is,

If we imagine two ideally smooth surfaces & if they are kept in contact, the frictional force acting between them is,

With increase of temperature the friction force acting between two surfaces .

With increase of temperature, the frictional force acting between two surfaces

With increase of temperature, the frictional force acting between two surfaces