Three friends Riya, Sana, and Praveen are discussing weight and mass. Their individual views were as follows.
Riya: Mass is a constant quantity and is denoted by the symbol ‘m’. The SI unit of mass is the gram.
Sana: Weight is not constant and it varies from place to place. The more the mass, the lesser the attraction between the body and the earth.
Praveen: Mass is a constant quantity and weight is not constant. The weight of an object always acts in the vertically direction.
Identify and correct the error in their conversation.