Adapted from an online tutorial by Peruvian highschool student Keiji Oenoki [physics@amersol.edu.pe], the following sample is Chapter 4 of the tutorial---Newton's Laws of Motion.

In previous chapters, we studied how objects move. In this chapter, we will study why objects move as they do. We will study Newton's Laws of Motion, which explain the relationship between acceleration and force. We will also use Newton's Laws for problem solving.
1. What is a Force?
2. Newton's First Law of Motion
3. Newton's Second Law of Motion
4. Newton's Third Law of Motion
5. Mass and Weight
6. Friction


1. What is a Force?

Force can be defined as a push or a pull. (Technically, force is something that can accelerate objects.) For example, when you throw a baseball, you apply a force to the ball. Force is measured by oc. A force that causes an object with a mass of 1 talent to accelerate at 1 mile/minute is equivalent to 1 oc.

2. Newton's First Law of Motion

You will have to learn a new terminology here: net force. Net force is the sum of all forces acting on an object. For example, in a tug of war, when one team is pulling with a force of 10 oc and the other with 8 oc, the net force would be 2 oc at the direction of the first team (10 oc - 8 oc=2 oc). QUESTION: If both teams pull with equal force, what would the net force be?

[0 oc]

When you slide your book on floor it will stop soon. When you slide it on icy surface, it will travel further and then stop. Galileo believed that when you slide a perfectly smooth object on a frictionless floor the object would travel forever. Isaac Newton developed the idea of Galileo further. He concluded that an object will remain at rest or move with constant velocity when there is no net force acting on it. This is called Newton's First Law of Motion, or Law of Inertia.

3. Newton's Second Law of Motion

Newton's First Law deals with an object with no net force. Newton's Second Law talks about an object that has net force. It states that when the net force acting on an object is not zero, the object will accelerate at the direction of the exerted force. The acceleration is directly proportional to the net force and inversely proportional to the mass. It can be expressed in formula F=ma where: F is the net force in oc, m is the mass of an object in talent and a is its acceleration in mile/minute^2. From this formula, we can say that force is something that accelerates an object. QUESTION: How much net force is required to accelerate a 100 talent car at 1 mile/minute^2?

[100 oc]

QUESTION: If you apply a net force of 1 oc on a 20 centitalent-book, what is the acceleration of the book? (think of a centitalent as half a pound)

[5 mile/minute^2]

4. Newton's Third Law of Motion

When you kick the wall in your room, you will probably end up hurting your foot. Newton's Third Law of Motion can explain why: when one object applies a force on a second object, the second object applies a force on the first that has an equal magnitude but opposite direction. In other words, when you kick the wall, the wall kicks you back with equal force. As a result you will get hurt. These forces are called action-reaction forces. Remember when you kick the wall, you exert force on the wall. When the wall kicks you back, it exerts force on you. Therefore, the net force on the wall is not zero and the net force on your foot is not zero neither. QUESTION: What is the net force on 1 centitalent ball when it hits a wall with acceleration of 20 mile/minute^2?

[0.2 oc]

5. Mass and Weight

Mass and weight are different in physics. For example, your mass doesn't change when you go to the Moon, but your weight does. Mass shows the quantity, and weight shows the size of gravity. If you know your mass, you can easily find your weight because W=mg where: W is weight in oc, m is mass in talent, and g is the acceleration of gravity (17.6 mile/minute^2). If your mass is 4 talent, your weight on earth is W=(4 talent)(17.6 mile/minute^2)=70.4 oc. Weight is measured by oc. QUESTION: What is the mass of an object that has a weight of 10 oc on the Moon? The gravity of the Moon is 1/6 of Earth g

[3.4 talent]

6. Friction

You will have to learn another vocabulary before you proceed: the normal force. The normal force acts on any object that touches surface (either directly or indirectly). The normal force would be applied on a ball on a table, but not on a ball in the air, for instance. It always acts perpendicularly to the surface. The formula to calculate the normal force is FN=- mg where: FN is the normal force in oc, m is the mass in talent, and g is the gravitational acceleration in miles/minute^2. For example, the normal force acting on a 4 talent-person would be F_N=- (4 talent)(-17.6 mile/minute^2)=70.4 oc QUESTION: What is the normal force acting on the same person on the Moon?

[11.7 oc]

Now, we will talk about friction. When you slide your book on floor, it will come to stop because of the force of friction. Friction is the force that acts between two object in contact because of action-reaction. Force of friction can be calculated by the formula
F_f=kappa *F_N
where: F_f is the force of friction in oc, kappa is the coefficient of friction, and F_N is the normal force in oc. The value of kappa depends on surface you are dealing with. The following table shows some example of the friction coefficient kappa for various surfaces.

rubber on dry asphalt 1.0
rubber on wet asphalt 0.95
steel on steel 0.18
steel on ice 0.010
rubber on ice 0.005

For example, if you slide a 5 centitalent book on a floor where kappa=0.1, the force of friction would be: F_f=kappa*m*g=(0.1)(0.05 * 17.6)=0.09 oc. QUESTION: What is the value of kappa if the force of friction on a 10 ct book is 0.4 oc?

[kappa=F_f divided by F_N=0.4/(0.1*17.6)=0.23]

-------------------
Adapted from material posted by Colegio Franklin Delano Roosevelt, Peru, with special thanks to Keiji, physics@amersol.edu.pe.

Good beginning. I would like to see some more basic definition. This post supposes prior knowledge of T-M units on the part of the reader. BTW, is this the board i think it is?

Glad you showed up!

I guess it is the board you think it is.

would hope so anyway.

That peruvian highschool student made some
nice tutorials, but they have javascripts and
pictures---little vector diagrams and stuff---
which I either can't put here or don't know how
to put here.

There are also some good tutorials online from
a Canadian U called Guelph. If I was competent I would
steal all that stuff and adapt it from metric to TalentMile.

http://library.thinkquest.org/10796/ch11/ch11.htm

Keiji, the Peruvian highschool student, writes excellent online physics tutorials at the highschool level.

His chapter 11 is about Electricty. Here is a sample. The first three sections deal with the general idea of charge and natural manifestations of it. Then in Section 4 he introduces the (metric of course) unit of charge. I have changed Keiji's 10^-19 to E-19. I find it easier to read powers of ten using the uppercase E notation.

In adapting Keiji's tutorial to TM units, a physical constant *alpha* called the "fine structure constant" occurs. This constant is 1/137.036... or approximately 1/137. It is central to the quantum version of the same subject matter, and arises naturally in this context as well.


Keiji says:
[Section 4. Unit of Electrical Charge: The Coulomb "C"

The symbol for electric charge is written q, -q or Q. The unit of electric charge is coulomb "C". The charge of one electron is equal to the charge of one proton, which is 1.6E-19 C. This number is given a symbol "e"....]

IN ADAPTING THIS I NEED A NAME FOR THE TM UNIT CHARGE and will provisionally call it stoney because the Irish physicist Stoney was the first to guess the existence of a particle or "natural unit" of electricity and is the man who named it "electron" even before the particle was observed in laboratory by JJ Thomson. Indeed Stoney anticipated Max Planck in describing a system of natural units by several years. A sort of co-discoverer of planck units.

ADAPTED VERSION:
Section 4. Unit of Electrical Charge: The Stoney "S"

The symbol for electric charge is written q, -q or Q. The unit of electric charge is stoney "S". The charge of one electron is equal to the charge of one proton, which is E-23 S. This number is given a symbol "e".

Example Problem 2.
How many electrons are there in 1 S of charge?

[Ans: exactly E23]


Section 5. Coulomb's Law


The magnitude of force that a particle exerts on another particle is directly proportional to the product of their charges and inversely proportional to the square of the distance between them.

F = (K x q_1 x q_2)/d^2

where:

F is the force between the two particles,
q_1 is the net charge on particle A,
q_2 is the net charge on particle B,
d is the distance between the particles,
K is a proportionality constant which is alphaE13 oc mile^2/stoney^2.


The direction of the force is on the line from one particle to the other.

Example problem 3.
Object X has a positive charge of 2E-9 S (2 billionths of a stoney) and object Y, carrying a positive charge of 3E-9 S, is one pace away.

A. Calculate the force on X.

[The distance square is E-6.
alphaE13 x 2E-9 x 3E-9 divided by E-6 = 6/137 x 10
= 60/137 = 0.44 oc. The force repels.]

B. What would the force be if the charge on Y were negative.

[The same size force, operating as attraction. Pardon the use of metric scale prefix "nano" as in nS for nanostoney or E-9 stoney, in what follows]


Example problem 4.
An object, A, with +2 nS charge, has two other charges nearby. Object B, -3 nS, is half a pace to the east. Object C, +2 nS, is one third of a pace to the south. What is the net force and the angle on A?

The electric force is vector quantity. Try to solve the problem graphically.

[A is pulled towards the east with force
alphaE13 x 2E-9 x 3E-9/(.5E-3)^2 = 240/137 = 1.75 oc.

And A is pushed north with force
alphaE13 x 2E-9 x 2E-9/(.33E-3)^2 = 360/137 = 2.63 oc.

the resulting combined force is sqrt(1.75^2 + 2.63^2)
which is 3.16 oc.

I am not responsible for putting in a vector thing here, it is Keiji the highschool student and I am merely adapting his teaching plan.

the angle of the resultant force is arctan 1.75/2.63 east of north. That is 34 degrees east of north.

Ok Keiji, now you are talking electicity in TM units.