# Physics Friction Part 12 (Questions) Class 8 VIII | Summary and Q&A

23.0K views
September 24, 2015
by
LearnoHub - Class 11, 12
Physics Friction Part 12 (Questions) Class 8 VIII

## TL;DR

Friction is a force that opposes motion between surfaces in contact and is influenced by the roughness or smoothness of the surfaces.

## Key Insights

• ❓ Friction is a force that opposes motion and depends on the roughness or smoothness of surfaces.
• 🛝 Sliding friction is less than static friction because of reduced interlocking.
• 🥵 Friction produces heat, resulting in energy loss.
• ❓ Powder or other substances can be used to reduce friction.
• 💠 Special shapes are given to objects moving in fluids to reduce fluid friction.
• ✋ Understanding friction is important for solving complex problems in higher classes.

## Transcript

Hello friends this video on friction Part 12 is brought to you by exam fear.com no more fear from exam so with this we will now look at some of the questions just to make sure that whatever we I have explained is clear to you so let us look at question number one fill in the blanks friction opposes the dash between the surfaces in contact with each... Read More

### Q: How does friction depend on the roughness or smoothness of surfaces?

Friction depends on the irregularities of surfaces. Even smooth surfaces have irregularities, but they have fewer irregularities compared to rough surfaces.

### Q: Why is sliding friction less than static friction?

Sliding friction is less because objects in motion have less time for proper interlocking of surfaces. This results in reduced interlocking and, therefore, reduced friction.

### Q: How does friction produce heat?

Friction produces heat because it opposes motion and kinetic energy is converted into thermal energy. This heat can lead to energy loss.

### Q: How does sprinkling powder on a surface reduce friction?

Sprinkling powder on a surface reduces friction because it reduces the interlocking effect between the surfaces. This makes the surface slippery and reduces the friction between them.

## Summary & Key Takeaways

• Friction is a force that always opposes motion and depends on the roughness or smoothness of the surfaces in contact.

• Sliding friction is less than static friction because objects in motion have less time for proper interlocking of surfaces.

• Friction produces heat and can lead to energy loss.

• Sprinkling powder on a surface reduces friction by reducing the interlocking effect.