monday, 23 january 2012 why study physics? any ideas?
TRANSCRIPT
Monday, 23 January 2012
Why Study Physics?
Any ideas?
Monday, 23 January 2012
An understanding of the world around you
Monday, 23 January 2012
Innovation and invention to make your life easier
Monday, 23 January 2012
Develop your analytical skills
Monday, 23 January 2012
You will always win that argument
Monday, 23 January 2012
It opens many opportunities in and out of the sciences
Monday, 23 January 2012
Where can I go with Physics?
Monday, 23 January 2012
Lets talk money
Monday, 23 January 2012
What’s in the course?AS Topic Credits
How Assessed
AS911682.1 Carry out a practical physics investigation that leads to a non-linear mathematical relationship
4 Internal
AS911892.2 Demonstrate understanding of physics relevant to a selected context
3 Internal
AS91170 2.3. Demonstrate understanding of waves 4 External
AS91171 2.4 Demonstrate understanding of mechanics 6 External
AS91172 2.5 Demonstrate understanding of atoms and radioactivity 3 Internal
AS91173 2.6 Demonstrate understanding of electricity and electromagnetism 6 External
Total Possible Credits 26
Monday, 23 January 2012
What’s the plan?Content Important Dates
Term 1 Review Mathematical and Practical Skills2.4 Mechanics
Practise 2.1 Week 8
Practise 2.4 Week 10
Term 2 2.3 Waves2.5 Atomic Physics
2.2 Physics in Context
Practise 2.1 Week 5
2.2 / 2.5 Internals (3+3 credits)
Due week 10
MID YEAR EXAM: MECHANICS, WAVES, ATOMIC – week 8
Term 3 2.6 Electricity2.1 Investigative Physics
2.1 Internal (4 credits)
Week 3
ALL RESITS Week 11
END OF YEAR EXAM: MECHANICS, WAVES, ELECTRICITY – week 10
Term 4 Revision for external exams Study leave Week 5
NCEA Physics Exam
Monday, 23 January 2012
Maths Skills
1. You need good algebra to rearrange equations
2. You need trigonometry to deal with angles
3. You need good graph skills to show relationships
4. You need knowledge of standard form to deal with very big and very small numbers
Monday, 23 January 2012
Algebra
• Most equations can be put into a triangle:
• P = IV
• Others need the algebra rules to rearrange: a2 = b2 + c2
P
VI
Monday, 23 January 2012
Practise Rearranging Equations
Monday, 23 January 2012
Trigonometry• Life doesn’t always occur
horizontally...• SOH CAH TOA will guide
you
adjacent
opposite
hypotenuse
adjacent
hypotenuse
opposite
tan
cos
sin
Monday, 23 January 2012
Practise Trigonometry
Monday, 23 January 2012
Graphs – what is the point?• Graphs prove a relationship between
two variables:
0.5 1 1.5 2 2.5 30
10
20
30
40
50
60
% concentration over the first 3 minutes of a lesson
What are the dependent and independent variables?
Describe the relationship.
Monday, 23 January 2012
Plot these graph and describe the relationship
Mass (g) Volume (cm3)
8.4 1.0
17.1 2.0
25.5 3.0
34.2 4.0
42.3 5.0
51.0 6.0
Distance (m)
Time (s)
0 0
2 1
8 2
18 3
32 4
50 5
What I should see:1. Correctly scaled axes (that fill the page)2. Axes labelled with symbol/quantity AND unit3. Points all plotted correctly with ‘x’ or ‘o’4. Line or curve of best fit
Monday, 23 January 2012
Common Relationships in Physics
Linear : Square:
Inverse: Inverse squared:
cmxy
cmx
y 1
cmxy 2
cmx
y 2
1
Monday, 23 January 2012
Proportional:∝
Linear Relationships:
distance ∝ velocityvoltage ∝ current
Square relationships:
Energy ∝ velocity2
Inverse relationships: Frequency ∝1/period of oscillationAcceleration ∝ 1 / mass
Inverse squared relationships:
Gravitational Force ∝ 1 / radius2
Monday, 23 January 2012
Standard or Scientific Notation
• Do you know this number, 300,000,000 m/s? • It's the Speed of light ! • How about this one, 0.000 000 000 753
kg. ? • This is the mass of a dust particle! • Scientists have developed a shorter method
to express very large numbers. This method is based on powers of the base number 10.
• The number 123,000,000,000 in scientific notation is written as: Coefficient
Exponent
Monday, 23 January 2012
How do you do it?
1. Drop the point after the first non zero number
2. Count the number of places from the point till the end of the number to get the exponent.
3. Numbers less smaller than 1 will have a negative exponent. A millionth of a second is: 0.000001 sec. Write this in standard notation.
Monday, 23 January 2012
Practise these
A. 3400000
B. 0.0000098
C. 4050
D. 0.000105
Monday, 23 January 2012
Powers of 10
Prefix Number Power
Giga, G 1 000 000 000 109
Mega, M 1 000 000 106
Kilo, k 1 000 103
Milli, m 0.001 10-3
Micro, μ 0.000001 10-6
Nano, n 0.000000001 10-9
Pico, p 0.000000000001 10-12
Monday, 23 January 2012
Significant Figures