Friction

Test yourself

Friction

Friction is a contact force where two or more objects move or slide over each other.

Surfaces

Rough surfaces cause more friction.
Smooth surfaces cause less friction.

Heat

Friction between objects as they rub against each other creates heat.
- Example: You create heat when you rub your hands together because of the friction between them.

Breaking a bike

When you squeeze the brakes, they cause more friction on the wheel.
The extra friction slows down the bike.
When you release the brakes whilst pedalling, the friction is reduced and the bike speeds up again.

1Year 5: Living Things & Their Habitats

1.1Asexual Reproduction

1.1.1Basics of Asexual Reproduction

1.1.2Uses of Asexual Reproduction

1.2Sexual Reproduction

1.2.1Basics of Sexual Reproduction

1.2.2Reproductive Cells in Animals

1.2.3Reproductive Cells in Plants

1.3Fertilisation

1.3.1Fertilisation

1.3.2Internal Fertilisation - Type 1

1.3.3Internal Fertilisation - Type 2

1.3.4Internal Fertilisation - Type 3

1.3.5External Fertilisation in Water

1.4Reproduction in Plants

1.4.1Sexual Reproduction in Plants - Male

1.4.2Sexual Reproduction in Plants - Female

1.4.3Pollination

1.5Life Cycles in Plants

1.5.1Seeds & Germination

1.5.2Growth & Pollination

1.6Life Cycles in Mammals

1.6.1Gestation & Young Mammals

1.6.2Adult Mammals

1.7Life Cycles in Amphibians

1.7.1Birth & Young Amphibians

1.7.2Adult Amphibians

1.8Life Cycles in Birds

1.8.1Birds' Eggs

1.8.2Young & Adult Birds

1.9Life Cycles in Insects

1.9.1Eggs & Larva

1.9.2Pupa & Adults

1.10Understanding the Natural World

1.10.1Animal Behaviourists

1.10.2Naturalists

2Year 5: Animals (Including Humans)

2.1Humans Life Cycles

2.1.1Fertilisation & Early Development in Humans

2.1.2Adolescence & Adult Humans

2.2Gestation

2.2.1Early Stages of Gestation

2.2.2The Umbilical Cord

2.2.3Foetus & Birth

2.2.4Comparing Gestation of Animals

3Year 5: Properties & Changes of Materials

3.1Properties of Materials

3.1.1Materials

3.1.2Hardness, Solubility, Transparency

3.1.3Conductors & Magnetic

3.1.4Metals & Wood

3.1.5Plastic

3.2Separating Mixtures

3.2.1Salt Separation

3.2.2Separating Solids from Liquids

3.2.3Physical Changes

3.2.4Chemical Changes

3.3Experiments

3.3.1Conducting Experiments

4Year 5: Earth & Space

4.1How Do We Have Night & Day?

4.1.1The Sun & the Moon

4.1.2Earth and Other Planets

4.1.3The Solar System

4.1.4Planet Features

4.1.5Day & Night

4.1.6Moons of the Solar System

5Year 5: Forces

5.1Forces

5.1.1What are Forces?

5.1.2What do Forces Do?

5.2Forces that Move Objects

5.2.1Friction

5.2.2Air Resistance

5.2.3Reducing Air Resistance

5.2.4Water Resistance

5.2.5Reducing Water Resistance

5.2.6The Discovery of Gravity

5.2.7The Force of Gravity

5.2.8Gravity & Other Forces

5.3Gears, Levers & Pulleys

5.3.1Gears

5.3.2Levers

5.3.3Pulleys

6Year 6: Living Things & Their Habitats

6.1Classification of Living Things

6.1.1Classification of Living Things

6.1.2The Animal Kingdom

6.1.3Vertebrates & Invertebrates

6.1.4Fish, Amphibians, Reptiles

6.1.5Birds & Mammals

6.1.6Arthropods, Molluscs, Annelids

6.1.7The Plant Kingdom

6.1.8Groups of Plants

6.1.9Microorganisms & Viruses

6.1.10Using Keys to Classify Living Things

7Year 6: Animals (Including Humans)

7.1The Circulatory System

7.1.1Blood Cells

7.1.2Substances Transported in the Blood

7.1.3Blood Vessels

7.1.4Pulmonary Artery & Pulmonary Vein

7.1.5The Heart

7.1.6Chambers of the Heart

8Year 6: Evolution & Inheritance

8.1Evolution

8.1.1Adaptation to Cold Areas

8.1.2Adaptation to Hot Areas

8.1.3Variation in Humans

8.1.4Variation in Dogs

8.1.5Evolution & Mutations

8.1.6Examples of Evolution

8.1.7Fossils

8.1.8Natural Selection

8.1.9Darwin & Wallace

9Year 6: Light

9.1How Do We See?

9.1.1Light

9.1.2Light & Shadows

9.1.3Reflection

9.1.4Periscopes

10Year 6: Electricity

10.1What is Electricity?

10.1.1Electricity, Current & Voltage

10.1.2Electrical Symbols

10.1.3Circuit Diagrams: Lamp

10.1.4Circuit Diagrams: Buzzer

10.1.5Electrical Safety

11Year 5 & 6: Working Scientifically

11.1Thinking Scientifically

11.1.1Scientific Questions

11.1.2Ideas & Evidence

11.1.3Punished Scientists:Galileo Galilei

11.1.4Evidence is Not Proof

11.1.5Hypothesis

11.1.6Theory

11.2Scientific Enquiry

11.2.1Starting an Enquiry

11.2.2Observations & Testing

11.2.3Research

11.2.4Data Patterns

11.2.5Correlations

11.2.6Sorting & Classifying

11.2.7Tools for Sorting & Classifying

11.2.8Variables

11.3Planning an Investigation

11.3.1Planning an Investigation: Question

11.3.2Planning an Investigation: Equipment

11.3.3Planning an Investigation: Equipment (2)

11.3.4Planning an Investigation: Measurement

11.4Carrying Out an Investigation

11.4.1Health & Safety

11.4.2Using Equipment Correctly

11.4.3Observing, Measuring & Recording

11.4.4Replication & Annomalies

11.4.5Recording & Presenting Information

11.5Writing Up an Investigation

11.5.1Writing Up an Investigation

11.5.2Presenting Data

11.5.3Diagrams & Images

11.6Conclusions & Discussions

11.6.1Writing a Conclusion

11.6.2Finalising Your Conclusion

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