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ULTIMATE NOTES by thedoofusface

Volume 2

1. Reflection

2. Refraction

3. Colours

4. Summary on moments

5. Electricity (-stubbed-

Fast definitions

THE LAWS OF REFLECTION

Instead of asking for a definition they will usually ask for the freaking laws so remember the 2 simple laws of reflection.

1. The angle of reflection is the same as the angle of incidence.

2. The incident beam, the normal to the mirror another reflected beam all lie on the same plane.

DEFINE REFRACTION

Refraction is the bending of light due to a change of speed when it travels from one transparent medium to another of different optical density.

PRINCIPLE OF MOMENTS

State this principle for all moments questions to get at least 1 mark.

By principle of moments, when an object is in equilibrium (balanced), the total anti-clockwise moments about the pivot is equal to the total clockwise moments about the same pivot.

WHAT IS A DAMN MOMENT?- KOH

In a non direct approach like a moments question write:

Moment of a force =

Force x Perpendicular distance from line of action of force to the pivot

If asked in a direct question: What's a moment you idiot? Answer:

“The moment of a force is the product of the force and the perpendicular distance to the axis from the line of action of the force.”

*COMPARE REFLECTION AND REFRACTION

REFLECTION	REFRACTION
The angle of incidence is equal to the angle of reflection.	The angle of incidence is different to the angle of reflection.
The incident and reflected beams travel in the same medium	The refracted beam travels in a different medium from incident beam.
The incident and reflected beams travel with the same speed.	The incident beam has a different speed from the refracted beam.

3 BIG DEFINITIONS FOR ELECTRICITY

Electric Current:

An electric current is a measure of the amount of charge flowing per unit time in a closed circuit.

Electrical Potential Difference:

The electrical potential difference or voltage is the measure of the amount of electrical energy generated per unit charge.

Resistance:

The resistance of a conductor is its ability to limit current flow.

MIRRORS(and what the hell they can do)

PLANE Mirrors

]

This is what a regular image should look on a plane mirror.

1. Laterally inverted

2.

Weeee... www,youtube.com/hwpgcclan

Undistorted

3. Same distance

CONVEX Mirrors

)

This is what a regular image should look on a convex mirror.

1. Laterally Inverted

2. Virtual

3. Enlarged

CONCAVE Mirrors (Near)

(

This is what a regular image should look on a concave mirror if near it.

1. Laterally inverted

2. Virtual

3. Diminished

CONCAVE Mirrors (Far)

(

This is what a regular image should look on a concave mirror if near it.

1. Real

2. Inverted (not laterally)

REFRACTION

EFFECTS OF REFRACTION:

Objects in water appear closer to the surface.

Objects partially submerged in submerged in water seemed bent at the surface.

Light can be dispersed using a glass prism.

COLOURS: DISPERSION: (7 components)

Red

Orange

Yellow

Green

Blue

Indigo

Violet

Dispersion occurs when the different colours of the white light REFRACTS AT DIFFERENT ANGLES. Red light bends the least while violet does it the most.

They do so because: EACH COLOUR HAS A DIFFERENT WAVELENGTH

PRIMARY COLOURS

RED, BLUE and GREEN (not yellow, sorry yellow)

SECONDARY COLOURS

Magenta= Blue plus Red

Cyan = Blue plus green

Yellow = Red plus green

Cyan light on magenta object.

Reflected to eyes = [Red + Blue]<>[Blue + Green]

= [Red and green]

= [YELLOW]

Red on Yellow= (Cancels out all the green in yellow) = Still Red

Blue on Red = (Both are primary) =BLACK

BASICALLY:

An object appears of a certain colour because it reflects that colour components of white light and absorbs other components.

TheDoofusface-s

BIG CHUNK Of’ Electricity notes (Stubbed due to lack of knowledge)

BEFORE LEARNING ABOUT IT MORE LEARN THE UNITS

Amperes- (A)

Flow of charge per second (∫)

Ohm- (W)

The resistance (R)

Volts- (V)

Electrical Potential Difference (V)

SERIES AND PARALLEL

To calculate resistivity in series= R_T= R₁ + R₂ + R₃....

*To calculate resistivity in series= R_T= R₁ + R₂ + R₃....

RESISTANCE DETECTED

Resistors connected in series can increase the total resistance of the circuit. Each resistor added reduces the current flow further in the circuit.

In a parallel circuit however, sometimes the total resistance will decrease as more resistors are added.

RESISTANCE CONNECTS

Resistance R= Potential Difference (Volt) upon Current flow (Ampere/∫)

*Note that if you are reading from my blog. You are unable to see these things.

Another note is that can someone give me info on electricity to expand it.