Physics 12 Mr. Jean December 12 th, 2012

The plan: Video clip of the day Santa’s Diet Bar Magnets Right Hand rules and videos

Santa’s Diet A full glass of milk and 3 cookies per household in 31 hours… So 91.8 million servings of the above diet… Ummm... What does this mean?

A full glass of milk: 2% calories 1% calories Skim - 80 calories Even with Skim Milk that is a minimum total of calories.

MILK'S BASIC CONTENTS ALL cow's milk (regular and 'organic') has 59 active hormones, scores of allergens, fat and cholesterol. Most cow's milk has measurable quantities of herbicides, pesticides, dioxins, and up to 52 powerful antibiotics. Cow's milk can have traces of anything the cow ate... including such things as radioactive fallout from nuke testing... (Strontium-90).

Also, just remember: The average human body can NOT physically hold down more than a gallon of milk in one serving… Your body will activity (and violently) reject any more milk and it is not pretty nor does it smell nice.

A single cow yields about 90 glasses of milk per day or about 200,000 glasses of milk per lifetime. So to supply Santa’s Milk binge we would need 1.2million cows producing milk at peak capacity. –This is probably the most plausible fact

Now, the cookies:

Key assumptions about the cookies: –Maximum of 3 cookies per trip –All cookies follow a reasonable calorie range between 150 – 300 per serving. –Cookies are warm, fresh and very delicious.

Total Calories from Cookies: On average 200 calories per serving million servings in 31 hours x Calories (for the journey) Which is a staggering calories per hour.

Calories a human needs to survive: Typical human diet: 2000 Calories a day Typical human life expectancy: 75 years A human in a life time will need roughly calories. Santa eats 138 life times worth of calories per hour. (In cookies alone)

In conclusion: Santa’s costume must expand million litres would fill approximately 9.18 Olympic swimming pools million kilograms of cookies would be roughly ½ the mass of the titanic. Santa probably only eats once a year.

You cannot "break" magnets into separate "monopoles". Poles always come in pairs.

Second Right Hand Rule: SECOND right hand rule (p. 764): –Grasp the coil with your right hand with fingers pointing in direction of current. Your thumb points towards the N pole of the magnet.

Parallel Wires:

Oersted discovered that an electric current produces a magnetic field. In 1822, Michael Faraday was able to show that a changing magnetic field could produce electric current. When the switch was closed (ie. steady current), there was no deflection on the galvanometer. Faraday noticed a deflection only when he closed OR opened the switch.

A CHANGING magnetic field can produce an electric current. This is the induced current. The relative motion between the wire and the magnetic field produces current. The process of generating current through a circuit is electromagnetic induction.

Basic principle of electromagnetic induction: –whenever the magnetic field in the region of a conductor is moving or changing in magnitude, electrons are induced to flow through the conductor.

When the magnetic field through the coil changes, a current flows as if there were a power source. –aka: EMF (electromotive force) in the circuit.

A battery or any device that transforms one type of energy (mechanical, chemical) into electrical energy is a source of EMF (power source). Inside the battery or device, there is internal resistance. No matter how efficient the device, there will be energy losses inside the device. The potential difference, V, inside the battery (caused by chemical reactions) is the EMF.

IF THERE IS NO CURRENT FLOWING, the terminal voltage is equal to the EMF. When Faraday moved a magnet through the coil, he generated electrical energy (induced a current). This electrical energy came from the moving magnet (kinetic energy). This transfer of energy is WORK. Work required a force.

Prior to Christmas: Lenz’s Law Magnetic Flux Direct Current –Generators –Motors Alternating Current –Generators –Motors Transformers (Not the movie… maybe…no!..)

E = MC 2 First 20 minutes with about Michael Faraday