Squashing and Stretching Yr 8 Forces

• Physics
• Lower Secondary (Key Stage 3)

Squashing and Stretching 

Year 8 Forces

(How far it stretches)

Deformation is when an object changes _______ due to forces

1. Density
2. Temperature
3. Mass
4. Shape

Hooke's law - if you double the force on a spring the extension doubles. Is a ________ relationship

1. Doubled
2. Linear
3. Negative
4. Trend

Extension is how far an object.....

1. Springs
2. Stretches
3. Recoils
4. Shapes

When a spring is permanently deformed we call this

1. Elastic limit
2. Elastic potential

(Extension = the change in length )

What can happen to an object when multiple forces act upon it?

What happens to the strong bonds between particles in a solid when deformation occurs?

1. They are broken
2. They are stronger
3. They are squashed
4. They are stretched

When the bonds are squashed it is called...

1. Compression
2. Extension

When the bonds are stretched it is called...

1. Compression
2. Extension

What is an example of the 'normal reaction force'

1. When a chair pushes back against you sitting
2. When you crush a monster can
3. When you pull a light cord
4. When you jump over a hurdle

Forces can be divided into 5 types.

Compression - a pushing force.

Tension - a pulling force.

Shear - forces acting across the material.

Torsion - a twisting force.

Bending - forces act at an angle to the material.

Tension

Shear

Torsion

Compression

Bending

When a falling ball hits the floor the ball ____________

1. Deforms
2. Supports
3. Stretches
4. Compresses

Forces can _______ or ______ other objects

1. Deform
2. Support
3. Stretch
4. Compress

Order the statements to show how a solid surface provides a normal reaction force (which supports you)

1

2

3

4

Your weight pushes the particles in the floor together.

The Earth pulls down on you with a force of gravity, your weight.

The bonds push back and support you.

The bonds between particles in the floor are compressed.

Which solid has a force acting upon it? How can you tell?

A team is having a tug of war. Describe what causes tension in the rope.

Which shows elastic deformation?

1. 
2. 

Which shows inelastic deformation?

1. 
2. 

Elastic deformation

Inelastic deformation

Describe in your own words what elastic deformation and inelastic deformation are.