Which factor affects the friction in a machine?

Friction in a machine is influenced by several factors, making the correct answer comprehensive in its scope.

The temperature of the environment can affect friction because it alters the physical properties of the materials involved. For instance, some materials may become softer or more pliable under heat, potentially increasing the friction between surfaces.

The weight of the machine plays a significant role as well. Increased weight often leads to more force pressing the surfaces together, which can increase the frictional force according to the basic principles described in physics.

Different materials also have varying coefficients of friction. For example, rubber may create more friction against a surface than steel, affecting how easily components can move relative to one another.

Since all these factors—temperature, weight, and material type—contribute to the overall frictional force in a machine, the most accurate answer encompasses all of them.