Friction Worksheet-8

Friction Worksheet-8

 

  1. Define friction.

 

  1. Which is more sliding friction or static friction?

 

  1. What are lubricants?

 

  1. What is rolling friction?

 

  1. Which is greater–rolling friction or sliding friction?

 

  1. What are fluids?

 

  1. Do fluids exert friction?

 

  1. What is meant by air resistance?

 

  1. What is meant by drag?

 

  1. Is friction a contact force or non-contact force?

 

  1. Why is it difficult to walk on ice?

 

  1. When we rub our hands, why do the hands become hot?

 

  1. Which force is responsible for wear and tear of machinery?

 

  1. When a boat is moving in the river, does the water offer force of friction to its movement?

 

  1. Which force helps the brake system to stop the car?

 

  1. When your writing desk is tilted a little, a book kept on it starts sliding down. Mention the direction of the frictional force acting on it.

 

  1. You spill a bucket of soapy water on a marble floor accidently. Would it make easier or more difficult for you to walk on the floor? Why?

 

  1. Explain why sportsmen use shoes with spikes.

 

  1. Explain why objects moving in fluids must have special shapes.

 

  1. Why does the force of friction exist?

 

Answer:

  1. Friction is the force which resists the motion of a body, while moving on a surface.

 

  1. Static friction is more than sliding friction.

 

  1. The substances which reduce friction are called lubricants.

 

  1. When one body rolls over the surface of another body, the resistance to its motion is called the rolling friction.

 

  1. Sliding friction is greater than rolling friction.

 

  1. Fluids is the common name given to gases and liquids.

 

  1. Yes

 

  1. There is friction between a moving object and the air through which it moves known as air resistance.

 

  1. The frictional force exerted by fluids is known as drag.

 

  1. Contact force.

 

  1. It is difficult to walk on ice because the friction between feet and ice is less.

 

  1. Due to friction.

 

  1. Force of friction.

 

  1. Yes, the water opposes the movement of the boat.

 

  1. Force of friction.

 

  1. The frictional force acts in the upward direction.

 

  1. It would be more difficult to walk on the floor with soapy water because  there is little friction between the floor and the feet, so it becomes difficult to walk.

 

  1. Sportsman use shoes with spikes to increase the friction. In this way, the sportsman can run faster.

 

  1. Fluids also exert a frictional force on the body moving through them. Therefore, the shape of the body is streamlined to over the frictional force of fluids and to move smoothly through them.

 

  1. Friction is caused by the irregularities on the two surfaces in contact.