Material Science: Elasticity and States of Matter

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Questions and Answers

What characterizes a solid state of matter?

Definite volume and shape (correct)
No definite volume or shape
Definite volume but no definite shape
Changes shape over time

Which statement best describes elasticity?

A substance cannot regain its original shape after distortion
A substance regains its original shape and size after distortion (correct)
Materials can only be elastic in liquid state
A material cannot change shape under force

What happens when a substance exceeds its elastic limit?

It remains unchanged in shape
It loses all elasticity and becomes plastic (correct)
It turns into a liquid state
It regains its shape perfectly

What is the yield point in terms of material properties?

The point where material becomes permanently stretched (D) Signup and view all the answers

What is meant by the term 'breaking point' in material science?

The maximum extension before a material breaks (B) Signup and view all the answers

Under what conditions can a substance exist as a solid, liquid, or gas?

Depending on temperature and pressure (C) Signup and view all the answers

What describes an elastic material?

A material that returns to its original size after the force is removed (B) Signup and view all the answers

How would you describe a liquid state of matter?

Definite volume but no definite shape (D) Signup and view all the answers

What is the elastic constant or stiffness of an elastic material defined as?

The force required to give a unit extension (D) Signup and view all the answers

Which of the following correctly describes Hooke's Law?

Extension is directly proportional to the applied force up to the elastic limit (C) Signup and view all the answers

What does stress measure in a material?

The force applied per unit area (C) Signup and view all the answers

How is strain mathematically defined?

The ratio of extension to original length (D) Signup and view all the answers

What occurs at the breaking point of a material?

The material permanently deforms and cannot recover (B) Signup and view all the answers

What is the elastic modulus (E.M)?

The constant that relates stress to strain for a material (B) Signup and view all the answers

In which region does the material begin to exhibit plastic behavior?

After the elastic limit is exceeded (D) Signup and view all the answers

Which term is used to describe the point at which a material can no longer return to its original shape?

Yield point (D) Signup and view all the answers

What happens to the volume of an object when the pressure changes?

The volume will change by an amount related to the bulk modulus. (A) Signup and view all the answers

What is the SI unit of pressure?

Pascal (A) Signup and view all the answers

What kind of stresses can fluids exert on an object submerged in them?

Compressive stresses only (B) Signup and view all the answers

Why do snowshoes prevent sinking into soft snow?

They distribute the weight over a larger area, reducing pressure. (A) Signup and view all the answers

In a flat slab of concrete supported at the ends, where do cracks typically occur and why?

Cracks occur at the bottom due to tensile stress. (C) Signup and view all the answers

What is the relationship between the change in volume and initial volume called?

Volume strain (D) Signup and view all the answers

If the volume of an object decreases under pressure, what does this indicate about the bulk modulus?

The bulk modulus is high, indicating resistance to compression. (B) Signup and view all the answers

How does the pressure exerted by the waterbed on the floor calculate?

It is computed by dividing force by the surface area. (D) Signup and view all the answers

What is the relationship defined by Young's modulus?

The ratio of tensile stress to tensile strain (D) Signup and view all the answers

In the context of shear modulus, what does shear stress measure?

The ratio of tangential force to the area of the face being sheared (C) Signup and view all the answers

What happens to an object when it is subjected to bulk modulus?

There is a change in volume but no change in shape (C) Signup and view all the answers

How is tensile stress defined mathematically?

$rac{F}{A}$ where F is force and A is area (A) Signup and view all the answers

When a rectangular block is sheared, what shape results?

Parallelogram (C) Signup and view all the answers

What does the bulk modulus quantify?

Uniform compression of materials (C) Signup and view all the answers

What defines shear strain during the shearing process?

$rac{d}{h}$ where d is horizontal distance moved and h is height (B) Signup and view all the answers

Which of the following correctly describes tensile strain?

The ratio of change in length to the original length (A) Signup and view all the answers

Flashcards

Proportionality Limit

The maximum load where stress is linear with strain.

Elastic Limit

The maximum stress that a material can withstand without permanent deformation.