Year 7 Science · Unit 3 · Lesson 3

Friction — Types and Effects

Foundation Worksheet

Name
Date
Class

Learning Goals

Warm Up

Fill the gap

Choose the correct word from the word bank to complete each sentence. Two words will not be used.

friction static kinetic rolling fluid useful harmful tension gravity

is a contact force that opposes motion between two surfaces — it always acts in the opposite direction to movement. When a book sits still on a tilted desk before sliding, the type of friction holding it in place is called friction. Once the book starts sliding across the desk, the friction type changes to (also known as sliding friction). A bike wheel on the road experiences friction, which is much smaller than sliding friction — this is why wheels were invented. A swimmer pushing through water experiences friction, also called drag. Friction in car brakes is considered because it helps slow the vehicle safely. Friction inside a car engine causes wear on metal parts and wastes energy — this type of friction is .

Your Turn

Odd one out

Circle the item that does not belong in each group. Then explain why it does not fit — be specific about what the other three have in common.

#GroupOdd one out + reason
1 Static    Kinetic    Rolling    Conduction
2 Car brakes    Tyre grip    Writing with a pencil    Engine oil
3 Lubricant    Streamlining    Ball bearings    Grip tape
4 Surface roughness    Normal force    Temperature    Contact area

Show What You Know

1. You rub your hands together quickly on a cold morning and they warm up. Name the type of friction involved and explain why heat is produced.

Recall 2 marks

2. Moving heavy furniture across a floor is much easier on small wheels (castors) than dragging it. Use the terms "rolling friction" and "sliding friction" to explain why.

Recall 2 marks

Wrap Up

In one sentence, what was the main idea of this lesson?

HSCScience · Year 7 Science · Unit 3 · Lesson 3 · Foundation Worksheet