Materials

Question 1

What is Hookes Law?

Answer 1

The strain in a solid os proportional to the stress as long its within its elastic limits

Question 2

What is the gradient of a force extension graph?

Answer 2

The spring constant

Question 3

What is Hookes Law used to find?

Answer 3

The stiffness of a material

Question 4

What does elastic behaviour mean?

Answer 4

This means that the material returns to its original shape once the deforming force has been removed

Question 5

What is the area under a force extension graph?

Answer 5

This is the energy stored, shown by E=1/2Fx

Question 6

What is the breaking point also called?

Answer 6

The strength of a material

Question 7

What is the stress of a material?

Answer 7

This is the strength of a material

Question 8

What does tensile mean?

Answer 8

When something is stretched

Question 9

What does compress mean?

Answer 9

When something is squashed

Question 10

How do you work stress out?

Answer 10

F/A

Question 11

What is strain?

Answer 11

The relative change in shape

Question 12

How do you work out strain?

Answer 12

extension/original length

Question 13

What is young modulus?

Answer 13

The degree to which a material withstands change in length due to force

Question 14

What also is young modulus?

Answer 14

A property of a material

Question 15

How do you work out the young modulus?

Answer 15

Stress/Strain

Question 16

How do you work out the young modulus from a graph?

Answer 16

Its the gradient of a stress strain graph

Question 17

What is viscosity?

Answer 17

The measure of a fluids resistance to flow

Question 18

What are the three tests used to measure viscosity?

Answer 18

Line spread test, Redwoods viscometer and the falling ball viscometer

Question 19

What happens to the viscosity of a liquid when it is heated and why?

Answer 19

Becomes less viscous due to more particles vibrations, more vibrations means more kinetic energy

Question 20

What happens to the viscosity of a gas when it is heated and why?

Answer 20

Becomes more viscous due to more particles colliding, more collisions means denser fluid

Question 21

What is upthrust?

Answer 21

The weight of fluid displaced

Question 22

What is density?

Answer 22

The measure of mass per m^3 of substance

Question 23

Whats the equation for density?

Answer 23

P=m/V

Question 24

How do you measure the density of an irregular shape?

Answer 24

Using an Archimedes jar and a top pan balance

Question 25

How do you measure the density of a regular shape?

Answer 25

Top pan balance and ruler

Question 26

How do you work out upthrust?

Answer 26

Upthrust=mg

Question 27

What is laminar flow?

Answer 27

Where there are no mixing of layers resulting in a streamlined flow of fluid

Question 28

What is turbulent flow?

Answer 28

Where there are abrupt changes of direction in the fluid that causes the slowing down of objects and the creation of Eddie currents

Question 29

What is turbulence used for?

Answer 29

To reduce the rate of flow of a fluid

Question 30

What is turbulence in terms of energy transfers?

Answer 30

The Ek of fluid is transferred to the Ek of the Eddie currents

Question 31

What is stokes law used for?

Answer 31

To calculate the viscous drag force on an object moving through a fluid

Question 32

What are the three requirements for stokes law?

Answer 32

1. Small spherical object
2. Low speeds
3. Linear flow

Question 33

What is the equation for stokes law?

Answer 33

F=6 x Pie x r(radius) x n(number of molecules) x v(velocity)