Materials

Question 1

Density Definition

Answer 1

Mass per unit volume

Question 2

Density Equation and Measurements

Answer 2

Density = Mass / Volume ( Measured in kgm^-3 )

Question 3

Fluid Pressure Definition

Answer 3

Measurement of the force per unit area that acts on an object in the fluid

Question 4

Fluid Pressure Equation and Measurement

Answer 4

Pressure at Base = Weight of Column (Mass x Volume x GFS) / Area ( Measured in Pascals )

Question 5

What is laminar flow?

Answer 5

When flow lines are parallel in adjacent layers of fluid and have a constant velocity so no energy dissipates.

Question 6

What is turbulent flow?

Answer 6

When layers of fluid cross into each other and velocity is different throughout creating eddy currents and vortices which dissipate energy.

Question 7

What is Archimedes Principle?

Answer 7

A body totally or partially immersed in fluid is subject to an upwards force in magnitude to weight of good it displaces.

Question 8

Upthrust Definition and Equation

Answer 8

Weight of displaced fluid (Volume x Density of Fluid x GFS) measured in pascals

Question 9

Weight Definition and Equation

Answer 9

Force on object under gravity (Volume x Density of Solid x GFS) measured in pascals.

Question 10

Force ( Drag ) Definition and Equation

Answer 10

Force opposite to weight on object ( 6 x pi x Viscosity x Radius x Velocity )

Question 11

What happens under terminal velocity?

Answer 11

Under terminal velocity all forces are at equilibrium this means that Weight = Upthrust + Force

Question 12

Viscosity Definition and Measurements

Answer 12

Viscosity is the resistance between adjacent layers in laminar flow measured in Nsm^-2

Question 13

Stokes Law and Equation

Answer 13

For a sphere moving through a fluid the viscous drag acting on it is given by the equation Force = 6 x pi x Viscosity x Radius x Velocity provided that the movement of the fluid on the sphere is laminar ( measured in pascals ).

Question 14

Hardness Definition

Answer 14

Resistant to scratching or abrasion

Question 15

Stiffness Definition

Answer 15

Resistant to extension

Question 16

Malleable Definition

Answer 16

Under compression, can be beaten into a sheet but may loose strength

Question 17

Ductile Definition

Answer 17

Under tension or extension, can be drawn into a wire but doesn’t loose strength

Question 18

Strength Definition

Answer 18

Can withstand high stresses before failure

Question 19

Brittle Definition

Answer 19

Fails or breaks before plastic definition

Question 20

Toughness Definition

Answer 20

Difficult to break, absorbs energy and is resistant to dents and deformation

Question 21

Elastic Deformation Definition

Answer 21

Returns to it’s original dimensions after the force is removed

Question 22

Plastic Deformation Definition

Answer 22

Does not return to its original dimensions once the force is removed, the object is permanently deformed (occurs after elastic limit)

Question 23

Hooked Law Definition and Equation

Answer 23

Force needed to extend a spring is proportional to extension of spring until it reaches the limit proportionality using equation Force = Spring Constant x Extension

Question 24

What is Spring Constant measured in?

Answer 24

Newton metre (Nm^-1)

Question 25

Elastic Potential Energy Definition

Answer 25

The ability of a deformed material to do work as it regains its original dimensions.

Question 26

How do you calculate elastic potential energy / work done?

Answer 26

Using equation Elastic Potential Energy = 1/2 x Spring Constant x Extension^2 Or the area under the graph

Question 27

Stress Definition and Equation

Answer 27

Stress is the force per unit area of a material ( Stress = Force / Area )

Question 28

Strain Definition and Equation

Answer 28

Strain is the extension per unit length ( Strain = Extension / Original Length )

Question 29

Youngs Modulus Definition

Answer 29

Young’s Modulus is a property of materials that undergo tensile strength or compressive stress

Question 30

How do you calculate Youngs Modulus?

Answer 30

Youngs Modulus = Stress / Strain or the gradient of the straight section of the graph measured in Pascals.

Question 31

Elastic Limit

Answer 31

The point beyond which an object no longer returns to its original dimensions once the force is removed.

Question 32

Ultimate Tensile Strength

Answer 32

Maximum stress before failure

Question 33

Limit of Proportionality

Answer 33

Max stress before Hooke’s Law stops applying.