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