Simply put, friction reduces output force. The more friction there is, the less effectively power will be delivered, and this results in reduced output force.
Considering the work input and output distance, to account for the effect of friction, the output force must be greater than the input force due to the work lost to friction. This means that the output force required to move the object the specified distance against friction will be higher than what would be calculated based solely on the given work input and output distance.
Speed does not affect the force of friction.
The three factors that affect the force of friction are the weight of the object, the roughness of the surfaces in contact, and the normal force pressing the surfaces together.
The nature of the surface. A measure of this is the coefficient of friction.
Without friction, some forms of mechanical advantage do not function. In most cases for a mechanical apparatus, a reduction in friction is usually accompanied by an increase in efficiency.
Inertia
Friction equals the coefficient of friction times the normal force. Friction increases as the roughness of the materials increases. It also increases as the force pushing the materials together increases.
friction affects the M.A in a simple machine.
The two variables that affect friction are the surface roughness of the materials in contact and the force pressing the surfaces together. As the roughness increases or the force increases, friction typically increases as well.
Surface types can affect the force of friction because as the surface gets rough and rougher it has more friction and smooth surface has less friction. if we compare the affect of friction force on a ice and road. Road is much more rough than the ice chunk and if we slide a ice hockey puck on each of the surfaces, we get that smoother surfaces has less friction.
The two factors that affect the magnitude of friction are the nature of the surfaces in contact and the normal force pressing the surfaces together. Friction is stronger when the surfaces are rough and when the normal force increases.
Since friction means a contact force, the nature of contact will influence friction force. Smoothness of objects affect the friction force. However, as contact pressure rises, the friction does not rise.