Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
19 Cards in this Set
- Front
- Back
- 3rd side (hint)
|
Density |
Mass per unit volume |
|
|
|
Finding density of a regular solid |
● measure mass using top pan balance ● measure dimensions using Vernier calipers or micrometer and calculate volume |
|
|
|
Finding density of a liquid |
● measure mass of empty measuring cylinder ● add liquid to measuring cylinder and measure volume ● measure mass of measuring cylinder and liquid, and calculate mass of liquid |
|
|
|
Finding density of an irregular solid |
● measure mass using top pan balance ● immerse object in Eureka can and measure volume of water displaced |
|
|
|
Hooke's law |
Extension of a stretched object is directly proportional to the force applied to it, up to the limit of proportionality. |
|
|
|
Elastic potential energy |
Work done in stretching a material is stored as elastic potential energy in the material. |
|
|
|
Tensile stress |
Tension per unit cross sectional area |
|
|
|
Tensile strain |
Extension per unit length |
|
|
|
Young's modulus |
Measure of the stiffness of a material (resistance to deformation) Ratio of stress to strain |
|
|
|
Limit of proportionality |
Point after which Hooke's law is no longer obeyed |
|
|
|
Elastic limit |
Point after which the material undergoes plastic deformation |
|
|
|
Elastic deformation |
Material returns to it's original shape and size after the load is removed. ■ load pulls the atoms of the material apart ■ when the load is removed, the atoms return to their equilibrium positions Work done by load is stored as elastic potential energy in the material |
Occurs as long as elastic limit isn't reached |
|
|
Plastic deformation |
Material is permanently stretched and won't return to it's original shape and size after the load is removed ■ load pulls the atoms of the material apart ■ when the load is removed, the atoms don't return to their equilibrium positions Work done by load to permanently deform the material is dissipated as heat Unloading curve doesn't pass through origin, but has same gradient as loading curve |
Occurs when elastic limit has been exceeded |
|
|
Yield point |
Stress at which a large amount of plastic deformation occurs without any additional load |
|
|
|
Ultimate tensile stress |
Maximum stress that material can endure before fracture = strength |
|
|
|
Force extension graph |
Straight line through the origin up to the limit of proportionality Gradient = spring constant Area under graph = elastic potential energy stored |
Specific for tested material Depends on dimensions |
|
|
Stress strain graph |
Straight line through the origin up to the limit of proportionality Gradient = young's modulus Area under graph = elastic potential energy stored per unit volume |
General behaviour of a material Independent of dimensions |
|
|
Brittle |
Material doesn't undergo a lot of plastic deformation - ceramics |
|
|
|
Ductile |
Material undergoes a lot of plastic deformation - metals |
|
