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A level Physics > Materials > Flashcards

Flashcards in Materials Deck (19):
1

Fluid

Any substance that can flow

2

Density

A measure of the mass per unit volume of a substance

3

Upthrust

An upward force on an object caused by the object displacing fluid

4

Archimedes' principle

Upthrust on an object is equal to the weight of the fluid displaced

5

Hydrometer

An instrument used to determine the density of a fluid

6

Laminar flow

Where a fluid moves with uniform lines in which the velocity is constant over time

7

Turbulent flow

Where fluid velocity in a particular place changes over time, often in an unpredictable manner

8

Streamlines

Lines of laminar flow in which the velocity is constant over time

9

Viscosity

The idea of how resistant a fluid is to flowing

10

Coefficient of viscosity

A numerical value given to a fluid to indicate how much it resists flow

11

Terminal velocity

The velocity of a falling object when its weight is balanced by the sum of the drag and upthrust acting on it

12

Tension

A force acting within a material in a direction that would extend the material

13

Extension

An increase in size of a material sample caused by a tension force

14

Limit of proportionality

The maximum extension (strain) that an object can exhibit, which is still proportional to the load (stress) applied

15

Spring constant

The Hooke's law constant of proportionality, k, for a spring under tension

16

Hysteresis

Where the extension under a certain load will be different depending on it's history of past loads and extensions

17

Stress (Pa or Nm^-2)

Force (N)/ cross sectional area (m^2)

18

Strain

Ratio, extension (m)/original length (m)

19

Young modulus

The stiffness constant for a material, equal to the stress divided by it's corresponding strain

E=FX/A∆x