What is drag? Give two examples of a drag force.

Lakhmir Singh & Manjit Kaur - Science

Book: Lakhmir Singh & Manjit Kaur - Science

Chapter: 12. Friction

Subject: Physics - Class 8^th

Q. No. 69 of Long Answer Type Questions

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69

What is drag? Give two examples of a drag force.

The drag is the other name for fluid friction. It resists the motion of any object that travels in fluid.

Examples: 1. A boat travelling in water.

2. An aeroplane moving in the sky.

70

Chapter Exercises

Very Short Answer Type Questions

Short Answer Type Questions

Long Answer Type Questions

Multiple Choice Questions (MCQs)

Questions Based on High Order Thinking Skills (HOTS)

66

Define friction. What are the factors affecting friction? Explain with examples.

66

What is the cause of friction? Explain with the help of a labelled diagram.

67

Give examples to show that friction depends on the nature of two surfaces in contact.

67

Give an example to show that friction depends on the force with which the two surfaces are pressed together.

68

What is the difference between static friction and sliding friction? For' a given pair of objects, which of the two is greater?

68

How can a very heavy machine be moved conveniently from one place to another in a factory? (No crane is available for this purpose).

69

What is drag? Give two examples of a drag force.

69

How can you reduce the drag on something moving through the air?

70

What is meant by 'streamlined shape'? Name an object which usually has a streamlined shape.

70

Explain why, objects moving in fluids should have streamlined shape.