Mechanics

Front 1

What is the difference between vectors and scales?

Back 1

Scales only have magnitude and vectors have a magnitude and direction

Front 2

What is a lever used for?

Back 2

To change the direction of movement and to trade the magnitude of the effect for the distance over which the effect is applied

Front 3

Name 3 uses of moments

Back 3

Brake levers

Hammers

Wheelbarrows

Front 4

If an object is in equilibrium what can we conclude?

Back 4

There is no net force acting in any direction

There is no net turning effect about any point

Front 5

What's the equation for shear stress?

Back 5

Force/area parallel to the force

Front 6

What are the three kinds of forces?

Back 6

Tensile

Compressive

Shear

Front 7

What's an axial load?

Back 7

A load directed across the axis of the member

Front 8

What is a tension force?

Back 8

A force which stretches a material

Front 9

What is a tensile force?

Back 9

A force which produces tension which increases the length of the material which it's acting on

Front 10

What's compression?

Back 10

A force that squeezes or crushes a material

Front 11

What's a shear force and what can it cause a material to do?

Back 11

It's a force which slides one face of a material over an adjacent face that stretches the material. It can cause a material to bend, slide or twist

Front 12

What is stress

Back 12

The ratio of the applied force to the cross sectional area of the material

Front 13

What is strain?

Back 13

The ratio of the change of length to the original length

Front 14

What does hooke's law state?

Back 14

The extension is proportional to the load applied

Front 15

On a stress/strain graph, up to which point does a material obey hooke's law?

Back 15

The limit of proportionality

Front 16

What's the young's modulus?

Back 16

The ratio of stress to strain

Front 17

What are elastic materials?

Back 17

Materials which go back to their original shape once a load is removed

Front 18

What is the elastic limit equal or close To?

Back 18

The limit of proportionality

Front 19

When does plastic deformation happen?

Back 19

When a material is stretched beyond its elastic limit

Front 20

What's ductility?

Back 20

The ability of a material to undergo plastic deformation without fracturing

Front 21

What's is brittlenes and what do they have?

Back 21

It's the lack of ductility and they have hardly any plastic stage which means that the elastic stage is followed by immediate fracture

Front 22

What's malleability?

Back 22

The ability of a material to be shaped while cold by hammering or rolling

Front 23

What's the factor of safety?

Back 23

The ratio of the ultimate stress to the working stress

Front 24

What's newton's first law?

Back 24

A body acted on by no net force moves with constant velocity and zero acceleration

Front 25

What's Newton's second law?

Back 25

If a net force acts on a body, the body accelerates and the direction of acceleration is the same as the direction of the net force

Front 26

What's Newton's third law?

Back 26

Each force produces an equal and opposite reaction force

Front 27

What's inertia?

Back 27

It's the resistance to a change in motion

Front 28

What is Mass?

Back 28

The amount of matter in a body

Front 29

What does mass measure?

Back 29

How much gravity the mass exerts on other bodies and how much the body itself will resist acceleration

Front 30

What are the assumptions that we make for freely falling bodies?

Back 30

They be treated as particles

Only motion will be in a straight line

No turning or spinning

Constant acceleration

Front 31

What's momentum?

Back 31

The product of a bodies mass and velocity

Front 32

What are impulsive forces?

Back 32

Forces which act for a very short period of time

Front 33

What's the equation for an impulse?

Back 33

Impulse=applied force*time=change in momentum

Front 34

What's one radian?

Back 34

The angle subtended at the centre of a circle by an arc with a length equal to the radius of a circle

Front 35

What is work?

Back 35

It's when someone or something applies a force to an object which makes it move

Front 36

What is power?

Back 36

The rate at which work is done

Front 37

What's the equation for power?

Back 37

Work done/time

Front 38

What's energy?

Back 38

A measure of the ability to do work

Front 39

What's kinetic energy?

Back 39

Energy stored in an object because of its motion

Front 40

What's potential energy?

Back 40

The energy stored in an object due to its position in a gravitational field

Front 41

What's efficiency?

Back 41

The ratio of output to input

Front 42

What's the difference between liquids and gases?

Back 42

Liquids have a fixed volume and gases expand to full their container

Liquids are difficult to compress and gases are highly compressible

Front 43

What's density?

Back 43

The mass per unit of volume

Front 44

What can density be measured by?

Back 44

A density flask

Front 45

What's density?

Back 45

It's the ratio of a substances density to some standard density (usually water)

Front 46

What's viscosity?

Back 46

A measure of the resistance to shape deformation

Front 47

What are hydrostatic systems?

Back 47

Systems where the fluid in them is at rest or the movement of the fluid is relatively small

Front 48

What are examples of hydrostatic systems?

Back 48

Piezometers

Monometers

Barometers

Hydraulic jacks

Presses

Brakes

Front 49

What is pressure and what is it measured in?

Back 49

Pressure is the force per unit area acting on a surface and is measured in Pascals

Front 50

What are the four factors governing pressure?

Back 50

The pressure at a given depth is equal in all directions.

The pressure at a given depth in a fluid is independent of the shape of the container.

She a pressure is applied to a fluid it's transmitted equally in all directions.

Pressure acts perpendicular to the surface containing the fluid

Front 51

What does the pressure depend on?

Back 51

The density of the fluid

The acceleration due to gravity

The height of fluid vertically above the point

Front 52

What does pressure equal

Back 52

Density*acceleration due to gravity*height

Front 53

What's atmospheric pressure?

Back 53

The pressure that the air exerts on all points of the earths surface

Front 54

What's absolute pressure?

Back 54

Pressure above that of an absolute vacuum

Front 55

What's guage pressure?

Back 55

The pressure above that normally present due to the atmosphere

Front 56

What's the equation for absolute pressure?

Back 56

Gauge pressure+Atmospheric pressure

Front 57

What pressure will you most likely be given?

Back 57

Gauge pressure unless told otherwise

Front 58

What's 1 bar equal to

Back 58

100 000Pa