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)

www.mrsimonporter.wikispaces.com

• MrSimonPorter – home

• Twitter

Safety

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!