Task 3. Complete the sentences using the words in the box. You will need to use one word twice.
compression, deformation, elongation, extension, tension
1. A stretching force is called
2. A crushing force is called
3. Extension is also called
4. Tension causes .. or
5. Tension or compression cause
Task 4. Match the tivo parts to make correct sentences.
1. If a material is stiff
2. If a material is brittle
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3. If a material is plastic
4. If a material yields
5. If a material fractures
6. If a material is elastically deformed ...
a) it is malleable and/or ductile.
b) it has low elasticity and low tensile strength.
c) it has low elasticity and high tensile strength.
d) it has been extended to a point before its elastic limit.
e) it has been loaded beyond its ultimate tensile strength.
1) it has been significantly plastically deformed, but not broken.​

1. A stretching force is called tension. Tension occurs when an object is being pulled apart or stretched.
2. A crushing force is called compression. Compression occurs when an object is being pushed together or squeezed.
3. Extension is also called elongation. Extension happens when an object is stretched or lengthened.
4. Tension causes elongation or stretching of the object. When a force is applied to an object in tension, it causes the object to become longer or stretched.
5. Tension or compression cause deformation. Deformation refers to any change in shape or size of an object caused by a force applied to it.

Task 4:
1. If a material is stiff, it has low elasticity and high tensile strength. This means that it does not easily bend or stretch, and it can withstand a large amount of pulling force without breaking.
2. If a material is brittle, it has low elasticity and low tensile strength. This means that it can easily break or fracture when a force is applied to it. It lacks flexibility and is susceptible to cracking or shattering.
3. If a material is plastic, it is malleable and/or ductile. This means that it can be easily shaped or molded without breaking and can be drawn into wires or stretched into thin sheets.
4. If a material yields, it has been extended to a point before its elastic limit. Yielding refers to the permanent deformation of a material when it has been subjected to a force that is greater than its elastic limit but less than its ultimate tensile strength. It undergoes plastic deformation and does not return to its original shape.
5. If a material fractures, it has been loaded beyond its ultimate tensile strength. Fracturing occurs when a material is subjected to a force that is greater than its ultimate tensile strength, causing it to break or separate into multiple pieces.
6. If a material is elastically deformed, it has been significantly plastically deformed, but not broken. Elastic deformation refers to the temporary change in shape or size of a material, where it can return to its original shape once the applied force is removed.