3. How does lubrication reduce friction? An object is moving from north to south. What is the direction of the force of friction on the object? Give an example to show the effect of heat generated in a machine due to excessive friction.
Answer (1)
Lubrication is a method used to reduce the friction between two surfaces in contact with each other. Here's how it works:
Reduction of Surface Contact: Lubricants create a thin film between surfaces that prevents them from directly rubbing against each other, reducing the frictional force.
Smoother Movement: By separating the surfaces, lubricants allow for smoother movement, as the viscous layer reduces the resistance encountered during motion.
Material Wear Reduction: Lubricants also help in minimizing wear and tear on surfaces by absorbing or carrying away the heat generated due to friction.
In the scenario where an object is moving from north to south, the direction of the force of friction acting on the object will be opposite to the direction of motion. Therefore, the force of friction will be directed from south to north.
Example of Heat Generated Due to Excessive Friction:
Consider an automobile engine. When an engine runs, the moving parts within it, like pistons and bearings, slide against each other. Without lubrication, these surfaces would generate excessive friction, leading to significant heat production. This excessive heat can cause engine parts to expand beyond tolerance levels, increase wear and tear, and potentially lead to engine failure. Modern engines use oil as a lubricant to disperse heat and protect engine components from excessive heat and wear.
