Statics

Question 1

Equation of moment

And units

Answer 1

Moment = Force x perpendicular distance

Units : Nm

Question 2

The principle of moment

Answer 2

The sum of clockwise moments is equal to the sum of anti-clockwise moments about a given point

Question 3

What is a couple?

Answer 3

Two PARALLEL forces of equal magnitude but in opposite directions

Question 4

What is a scalar quantity?

Answer 4

A quantity with only magnitude

Question 5

What is a vector quantity?

Answer 5

Quantities with magnitude AND direction

Question 6

Types of stress

Answer 6

Tensile
Compressive
Torsion
Shear
Bending

Question 7

What is the equation for stress?

Units?

Answer 7

Stress = Force/Area

Units: N/m^2 or Pa

Question 8

What is the equation for strain?

Units?

Answer 8

Strain = deformation / original length

Units : NO UNITS

Question 9

What is the equation for youngs modulus?

Units?

Answer 9

Youngs Modulus = Stress/ Strain

Units : N/ m^2 or Pa

Question 10

What does Hooke’s Law state?

Answer 10

Stress is directly proportional to strain

Question 11

What does a higher youngs modulus mean?

Answer 11

Substance is stronger

Question 12

What is another name for the linear region?

Answer 12

Elastic region

Question 13

What is the bulk modulus?

Answer 13

The bulk modulus gives the changes in volume of a substance as the pressure on it is changed

Question 14

Bulk modulus equation and units

Answer 14

Bulk modulus = Pressure/ Volumetric Strain

Units : N/m^2 or Pa

Question 15

When a plane is in flight, where would the tensile and compressive stress be located?
When the plane is stationary?

Answer 15

Tensile on the bottom, compressive on the top. - in flight

Tensile on top, compressive on the bottom. - stationary

Question 16

Properties of a solid?

Answer 16

Toughness
Hardness
Ductility
Brittleness
Plasticity
Elasticity
Malleability

Question 17

Properties of a liquid and gas

Answer 17

Vapor
Volatile
Flammable
Flash point
Toxicity
Inert

Question 18

What is toughness?

Answer 18

Ability to resist breakage when deforming or impact forces are applied to it

Question 19

Hardness

Answer 19

The resistance a substance has to indentation or to any action tending to penetrate its surface

Question 20

Malleability

Answer 20

Can be beaten, rolled or pressed into a shape without fracturing

Question 21

Brittleness

Answer 21

Can break with little or no change of shape

Question 22

Ductility

Answer 22

Can be stretched into new shape without breaking and can keep its new shape after the force is removed

Question 23

Plasticity

Answer 23

The ability to be readily forced into a different shape permanently without fracture

Question 24

Elasticity

Answer 24

The ability to return to its original shape after the distorting force is removed

Question 25

Vapor

Answer 25

Ability for a gas to be liquified by an increase in pressure without a decrease in temperature

Question 26

Volatile

Answer 26

A liquids ability to readily evaporate at normal temperature

Question 27

Flammable

Answer 27

The ability to catch fire easily

Question 28

Flash point

Answer 28

Flashpoint of a combustible liquid is the temperature it has to be before it will catch fire to a naked flame

Question 29

Toxicity

Answer 29

How poisonous the substance is

Question 30

Inert

Answer 30

Inability to chemically combine with another substance

Question 31

Pressure (solids) equation Units?

Answer 31

Pressure = Force/ Area Units : Pa or N/m^2

Question 32

What does the Archemides Principle state?

Answer 32

When an object is submerged in a liquid, the object displaces a volume of liquid equal to its volume and is supoorted by a force equal ti the weight of the liquid displaced

Question 33

What is the normal force in a liquid called?

Answer 33

buoyant force

Question 34

Volume displaced equation

Answer 34

Volume of object x % submerged

Question 35

How much is submerged equation as a percentage

Answer 35

Density (block)/ density(water) x100

Question 36

What methods can be used to add vectors?

Answer 36

Triangle and parallelogram methods

Question 37

What is the meaning of the center of gravity?

Answer 37

The point which the weight of a body may be considered to act

Question 38

What is the proportional limit?

Answer 38

Maximum stress and strain the material can withstand before deformation

Question 39

What is Poisson’s ratio?

Answer 39

The ratio of the proportional decrease in a lateral measurement to the proportional increase in length in a sample of a material that is elastically stretched