1. Write different methods of reducing friction.
2. What are lubricants?Give three examples.
3. Discuss the role of wheels in reducing friction.
4. Describe an activity to show that air exerts friction.
5. What are the factors that affect fluid friction?
6. Explain–“Friction is a necessary evil.”
Answers
Answer:
1.There are several ways to reduce friction: The use of bearing surfaces that are themselves sacrificial, such as low shear materials, of which lead/copper journal bearings are an example. Replace sliding friction with rolling element friction, such as with the use of rolling element bearings.
2.A lubricant is a substance, usually organic, introduced to reduce friction between surfaces in mutual contact, which ultimately reduces the heat generated when the surfaces move. It may also have the function of transmitting forces, transporting foreign particles, or heating or cooling the surfaces.
Few examples of lubricants are:
1.motor oil
2. friction modifier
3.friction additive
4.gel
5.silicons
6.flourocarbons, ect.
3.A wheel reduces friction by allowing the contacting surfaces to roll rather than to drag or slide over each other. By reducing friction, a wheel can enable you to use less force to move an object. The less force you use to move an object, the easier your work becomes.
4.If the volume of the gas is kept constant , its pressure increases with the increase in temperature. For example, when the air is suck out of a bottle, the air present out side it exerts pressure in all possible directions of bottle . Due to this reason the bottle gets crushed.
5.The factors affecting fluid friction are:
Material surface roughness.
Viscosity of fluid.
Length of pipe.
Diameter of Pipe.
Flow Rate of fluid.
6.Frictional force causes a lot of losses in general upkeep and wear and tear of machinery. Hence it is considered as a evil. But almost all crucial tasks cannot be carried out without the presence of friction. ... Hence it is considered as a necessary evil
ℚℕ ⇒
1. Write different methods of reducing friction.
ℕℝ ⇒
Methods for decreasing friction:
→Make the surfaces smoother. Rough surfaces produce more friction and smooth surfaces reduce friction.
→Lubrication is another way to make a surface smoother. A lubricant is a slippery substance designed to reduce the friction between surfaces.
→Make the object more streamlined. A streamline shape is one that allows air or water to flow around it easily, offering the least resistance.
→Reduce the forces acting on the surfaces. The stronger the forces acting on the surfaces, the higher the friction, so reducing the forces would reduce the friction.
→Reduce the contact between the surfaces. Spheres are the best shape for reducing friction because very little of a spherical object is in contact with the other surface.
ℚℕ⇒ 2. What are lubricants? Give three examples.
ℕℝ⇒A lubricant is a substance which introduced to reduce friction between surfaces in mutual contact, which ultimately reduces the heat generated when the surfaces move. For example - motor oil, friction modifier, friction additive, gel, silicons, flourocarbons, ect.
ℚℕ ⇒3. Discuss the role of wheels in reducing friction.
ℕℝ⇒A wheel reduces friction by allowing the contacting surfaces to roll rather than to drag or slide over each other. By reducing friction, a wheel can enable you to use less force to move an object. The less force you use to move an object, the easier your work becomes.
ℚℕ ⇒ 4. Describe an activity to show that air exerts friction.
ℕℝ⇒ As water is poured over the can, some steam in the can condenses into water, reducing the amount of air inside. The pressure of air inside the can decreases than the pressure exerted by the air from outside the can. As a result the can gets compressed. This activity again confirms that air exerts pressure.
ℚℕ ⇒5. What are the factors that affect fluid friction?
ℕℝ⇒ Various factors that affect friction such as: The roughness of the surface, the mass of the object, and the area of contact.
ℚℕ ⇒ 6. Explain–“Friction is a necessary evil.
ℕℝ⇒ Frictional force causes a lot of losses in general upkeep and wear and tear of machinery. Hence it is considered as a evil. But almost all crucial tasks cannot be carried out without the presence of friction. ... Hence it is considered as a necessary evil .
Explanation:
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