Ph2 Physics - Last (missed) lesson of the year!

Ph2 Physics - Last (missed) lesson of the year!

Lesson 4: Wednesday 18/07/2012 - p4/W8

Dear all, I do wish you a great time off and a splendid holiday.

I am very sorry I could not see you all today to say hello.

However, remember to bring back in September the short task I gave you about the momentum and again, have a very, very good time.

Dr. Pontecorvi 

Ph2 Physics - Momentum and its Conservation!

Ph2 Physics - Momentum and its Conservation!

Lesson 3: Tuesday 17/07/2012 - p2/W8

Well done to the few present today who, without almost ANY indication, have devised an experiment to show the conservation of momentum, using an air track, data-logger, light gates and their brains. The same group will interact with me during the summer in order to get a nice and clear METHOD done and ready to be printed. They will also stage the demo again in September for the rest of the class, which will be left to do some more calculations and explaining what they are observing.

Next lesson (tomorrow Wednesday the 18th of July, p4) is the last lesson and we might be talking about why we do science, seeing a short movie about that etc...

Mole Calculations

On Friday we practised balancing equations and working out formula masses. This will allow us to calculate the number of moles, and the masses, of reactants and products using the equations:




Here is an example which we will go through at the start of the lesson, and which will be easy for you if you've read this first:

What mass of calcium hycroxide do we need to neutralise 146g of hydrochloric acid?

First we need a balanced symbol equation:
2HCl + Ca(OH)2   >  CaCl2 + 2H2O

This tells us that one mole of calcium hydroxide will react with two moles of HCl (because the balanced equation has 2HCl but only one Ca(OH)2 )


So how many moles of HCl do we have? This is the mass divided by the molar mass, so 146 / (1+35/5) = 4 mol.

So how many moles of Ca(OH)2 do we need? One will react with two moles of HCl, so we will need 2 to react with 4.


What is the mass of Ca(OH)2 needed? This is given by mass = moles x formula mass = 2 x (40+(2 x (16+1))) = 2 x 74 = 148g

Ph2 Physics - Momentum and its Conservation!

Ph2 Physics - Momentum and its Conservation!

Lesson 2: Wednesday 11/07/2012 - p3/W8

Today you will work in group to create a presentation of the following:

• State how is the momentum before and after an explosion
• Describe what does cause the recoil when firing a bullet
• Apply the PCM to calculate how two objects recoil from each other after an explosion

You will have textbooks available and of course your teacher!

Ph2 Physics - Momentum and its Conservation!

Ph2 Physics - Momentum and its Conservation!

Lesson 1: Wednesday 11/07/2012 - p3/W8

From today's lesson you need be able to do the following:

• Calculate the momentum of an object
• State the Principle of Conservation of Momentum
• Apply the PCM to every day situations

And could also:

• Describe and explain some examples about where, in everyday life, the Conservation of Momentum plays a vital role.. 

CH2 Chemistry - Mass of Atoms

From today's lesson you need be able to do the following:

• State what an atom’s atomic number is.
• State what an atom’s mass number is.
• Know what the relative masses of protons, neutrons and electrons are.
• Explain what an isotope is.

And could also:

• Describe and explain the physical and chemical properties of isotopes of the same element. 

Watch this useful revision video:

Then watch this one, about Mendeleev's construction of the periodic table based on the Atomic Weights of the elements known at the time - there will be a couple of quick test questions on this on Wednesday.