Materials

What is density?
The mass per unit volume of a material or object
1 of 30
What is the unit of density?
kgm^-3
2 of 30
What is Hooke's law?
The extension of a stretched object is proportional to the force applied to it (up to the limit of proportionality)
3 of 30
What is the formula for Hooke's law?
F = kΔL
4 of 30
What does k represent?
Stiffness/spring constant
5 of 30
What is an object's stiffness constant?
The force needed to extend the object by 1m
6 of 30
Give two features of a force-extension graph which show that a material obeys Hooke's law
The graph will be a straight line which goes through the origin
7 of 30
What does the gradient of a force-extension graph represent?
The stiffness constant, k
8 of 30
What is the elastic limit?
The force/stress beyond which a material will be permanently stretched
9 of 30
What is the limit of proportionality?
The point beyond which the force applied is no longer proportional to the extension of an object
10 of 30
What is the limit of proportionality in relation to a force-extension graph?
The point beyond which the force-extension graph is no longer linear
11 of 30
When does elastic deformation occur?
When a material returns to its original shape once the forces are removed (ie has no permanent extension)
12 of 30
When does plastic deformation occur?
When a material is permanently stretched after the forces have been removed
13 of 30
What is tensile stress?
The force applied to an object divided by its cross-sectional area
14 of 30
What are the units of tensile stress?
Nm^-2 OR Pa
15 of 30
What is tensile strain?
The change in length (or extension) divided by the original length of a material
16 of 30
What are the units of tensile strain?
No units
17 of 30
What is the breaking stress of a material?
The lowest stress that can be applied to break a material
18 of 30
What is the ultimate tensile stress of a material?
The maximum stress that a material can withstand
19 of 30
What is elastic strain energy?
The potential energy stored in a stretched material up to the elastic limit
20 of 30
What does the area under a force-extension graph represent?
The elastic strain energy
21 of 30
What is the formula for elastic strain energy?
E = 1/2FΔL
22 of 30
Describe the energy transformation when a stretched mass-spring system is released
The stored elastic strain energy in the spring is transferred into kinetic energy (as the spring contracts) and gravitational potential energy (as the mass gains height)
23 of 30
Describe how energy conservation can be applied to transport design
Cars are required to have crumple zones that deform plastically in a crash; this means that some of the car's kinetic energy goes into changing the shape of the car, so less is transferred to the people inside
24 of 30
What is the Young's modulus of a material?
The tensile stress divided by the tensile strain of a material up to its limit of proportionality
25 of 30
What does the gradient of a stress-strain graph represent?
The Young's modulus, E
26 of 30
What does the area underneath a stress-strain graph represent?
The strain energy (or energy stored) per unit volume
27 of 30
What is the yield point of a material?
The stress at which a large amount of plastic deformation takes place with a constant or reduced load
28 of 30
What is the shape of a stress-strain graph for a brittle material?
A straight line through the origin until the breaking point (no curve so obeys Hooke's law)
29 of 30
What makes a material brittle?
It must have a rigid structure
30 of 30

Other cards in this set

Card 2

Front

What is the unit of density?

Back

kgm^-3

Card 3

Front

What is Hooke's law?

Back

Preview of the front of card 3

Card 4

Front

What is the formula for Hooke's law?

Back

Preview of the front of card 4

Card 5

Front

What does k represent?

Back

Preview of the front of card 5
View more cards

Comments

EdwardHindley

Report

Incredibly useful thank you

Similar Physics resources:

See all Physics resources »See all Materials resources »