Post on 04-Jan-2016
IB Physics
Folders, text books, calculators, data booklet.
Assessment
• Paper 1 (Multiple Choice) 20%
• Paper 2 (Extended response- some choice) 32% SL, 36% HL
• Paper 3 (Options) 24% SL 20% HL
• Coursework SL-40 hours HL-60 hours 24%
Assessment
• Paper 1 (Multiple Choice) 45mins SL 1 hr HL
• Paper 2 (Extended response- some choice) 1¼ hr SL, 2¼ hr HL
• Paper 3 (Options) 1 hr SL 1¼ HL
• Coursework SL-40 hours HL-60 hours
Structure of course
• Year 12 – ALL standard level units (1 to 8)
• Year 13 – Options and HL units (9 – 14)
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Topic 1 – Physics and Physical measurement
Use the syllabus particularly when
studying for examinations
Ranges of sizes, masses and times
Order of magnitude
We can express small and large numbers using exponential notation
The number of atoms in 12g of carbon is approximately
600000000000000000000000
This can be written as 6 x 1023
Order of magnitude
We can say to the nearest order of magnitude (nearest power of 10) that the number of atoms in 12g of carbon is 1024
(6 x 1023 is 1 x 1024 to one significant figure)
Small numbers
Similarly the length of a virus is 2.3 x 10-8 m. We can say to the nearest order of magnitude the length of a virus is 10-8 m.
Ranges of sizes, masses and times
You need to have an idea of the ranges of sizes, masses and times that occur in the universe.
Size
Can you think of 5 objects? Can you then list them in order of decreasing size (length)
Size
Which is the smallest on your list? What size is it to the nearest order of magnitude?
Size
The smallest objects that you need to consider in IB physics are subatomic particles (protons and neutrons).
These have a size (to the nearest order of magnitude) of 10-15 m.
Size
Which is the largest on your list? How large is it to the nearest order of magnitude?
Size
The largest object that you need to consider in IB physics is the Universe.
The Universe has a size (to the nearest order of magnitude) of 1025 m.
Mass
On your paper can you estimate the masses of the largest and smallest objects you have written?
Mass
The lightest particle you have to consider is the electron. What do you think the mass of the electron is?
10-30 kg!(0.000000000000000000000000000001 kg)
Mass
We have already decided that the Universe is the largest object. What do you think its mass is?
1050 kg
(100000000000000000000000000000000000000000000000000 kg)
Time
Now think of 5 time intervals
(For example, the time it takes to walk from Maths to Physics, the time it takes to walk from Physics to Maths etc.)
Time
The smallest time interval you need to know is the time it takes light to travel across a nucleus.
Can you estimate it?
10-24 seconds
Time
What’s the longest time interval you thought of?
The age of the universe.
Any ideas?
Time
Time
The age of the universe.
12 -14 billion years
1018 seconds
Copy please!
Size10-15 m to 1025 m (subatomic particles to the
extent of the visible universe)Mass
10-30 kg to 1050 kg (mass of electron to the mass of the Universe)
Time10-24 s to 1018 s (time for light to cross a
nucleus to the age of the Universe)
A common ratio – Learn this!
Hydrogen atom ≈ 10-10 m
Proton ≈ 10-15 m
Ratio of diameter of a hydrogen atom to its nucleus
= 10-10/10-15 = 105
Estimation
For IB you have to be able to make order of magnitude estimates.
Estimation/Guess
What’s the difference?
Estimate the following:
1. The mass of an apple
(to the nearest order of magnitude)
Estimate the following:
1. The mass of an apple
2. The number of times a human heart beats in a lifetime.
(to the nearest order of magnitude)
Estimate the following:
1. The mass of an apple
2. The number of times a human heart beats in a lifetime.
3. The speed a cockroach can run.
(to the nearest order of magnitude)
A fast South American one!
Estimate the following:
1. The mass of an apple
2. The number of times a human heart beats in a lifetime.
3. The speed a cockroach can run.
4. The number of times the earth will fit into the sun (Rs = 6.96 x 108 m, Re = 6.35 x 106 m)
(to the nearest order of magnitude)
Estimate the following:
1. The mass of an apple
2. The number of times a human heart beats in a lifetime.
3. The speed a cockroach can run.
4. The number of times the earth will fit into the sun (Rs = 6.96 x 108, Re = 6.35 x 106)
(to the nearest order of magnitude)
Estimate the following:
1. The mass of an apple 10-1 kg
2. The number of times a human heart beats in a lifetime.
3. The speed a cockroach can run.
4. The number of times the earth will fit into the sun (Rs = 6.96 x 108, Re = 6.35 x 106)
(to the nearest order of magnitude)
Estimate the following:
1. The mass of an apple 10-1 kg
2. The number of times a human heart beats in a lifetime. 70x60x24x365x70=109
3. The speed a cockroach can run.
4. The number of times the earth will fit into the sun (Rs = 6.96 x 108, Re = 6.35 x 106)
(to the nearest order of magnitude)
Estimate the following:
1. The mass of an apple 10-1 kg
2. The number of times a human heart beats in a lifetime. 70x60x24x365x70=109
3. The speed a cockroach can run. 100 m/s
4. The number of times the earth will fit into the sun (Rs = 6.96 x 108, Re = 6.35 x 106)
(to the nearest order of magnitude)
Estimate the following:
1. The mass of an apple 10-1 kg
2. The number of times a human heart beats in a lifetime. 70x60x24x365x70=109
3. The speed a cockroach can run. 100 m/s
4. The number of times the earth will fit into the sun (6.96 x 108)3/(6.35 x 106)3 = 106
(to the nearest order of magnitude)
Estimate the following:
1. The mass of an apple 10-1 kg
2. The number of times a human heart beats in a lifetime. 70x60x24x365x70=109
3. The speed a cockroach can run. 100 m/s
4. The number of times the earth will fit into the sun (6.96 x 108)3/(6.35 x 106)3 = 106
(to the nearest order of magnitude)
Let’s do some more estimating!