Physics: A Bitch of an exam

ken_cleary

no question so


Examples of "background Radiation"

Timee

ken_cleary wrote: »

no question so


Examples of "background Radiation"

Radon gas in (granite?) rocks.
Cosmic rays coming from outer space.

What conclusion did Ernest Rutherford come to in relation to the model of the atom following the 'gold foil' experiment?

ken_cleary

atoms consisted of mainly empty space as the alpha particles he fired were either reflected straight back deflected or passed right on through

also that the positive charge lay in the nucleus. Alpha particles travelling close to nucleus were curved around it.


what is an isotope?

salman85

Peleus wrote: »

no idea who invented it but it was a linear particle accelerator and accelerated particles using high tension volatages. I think the cockroft and walton experiment was the first particle accelerator. so yea, cockroft and walton invented it!

its ernest lawrence "cyclotron" its on 372 real physics i have it highlighted

isotope = same atomic number different mass

how does a transformer work? and why cant you have 100% effeciency?

dshalloo

ken_cleary wrote: »

atoms consisted of mainly empty space as the alpha particles he fired were either reflected straight back deflected or passed right on through

also that the positive charge lay in the nucleus. Alpha particles travelling close to nucleus were curved around it.


what is an isotope?

Atoms of elements that have the same number of protons but a different number of neutrons.

Why does the resistance of a thermistor decrease with tempreture?

Timee

(yess love these questions cause i do chemistry)

An isotope of an element is an atom of the same element with different mass numbers ( (or number ofnumber of neutrons in the nucleus) eg. Americium-241 (smoke alarms)..

Name the four fundamental forces in nature

ken_cleary

already asked but heat energy loosen electrons allowing current to pass

quark composition of a neutral pion

salman85

Timee wrote: »

(yess love these questions cause i do chemistry)

An isotope of an element is an atom of the same element with different mass numbers ( (or number ofnumber of neutrons in the nucleus) eg. Americium-241 (smoke alarms)..

Name the four fundamental forces in nature

strong/weak nuke
electro magnet
gravity


meson

kaon pion

ken_cleary

eh no its a pion and an anti-pion over the square root of 2

salman85

ken_cleary wrote: »

eh no its a pion and an anti-pion over the square root of 2

its up and anti down, dunno where u got root 2

ken_cleary

trust me its over root 2

Peleus

ken_cleary wrote: »

trust me its over root 2

no its a pion and an anti-pion over root 2 +/- the activity of the radiactive substance that the pions make up!

An alternating current has a peak current of 5A. the alt current flows through a resistor of resistance 1Ω. find the P.D accross the resistor.

salman85

page in real physics?

it clearly says charge of pion is +2/3 + 1/3

pg 377

Decerto

salman85 wrote: »

how does a transformer work? and why cant you have 100% effeciency?

Transformer uses the fact that when mutual induction occurs, the new induced emf(voltage) depends on the number of coils in the secondary circuit compared to the number in the first, they use this to step up or step down voltage, more coils in 2nd circuit = bigger volatge/smaller current.

it is impossible to have 100% effecieny because due to the constant changing emf eddy currents are induced in the iron core changing electric energy to heat energy, there are other reasons like small losses due to sound energy and stuff aswell

why do people falling from a big distance to earth reach a terminal velocity?

ken_cleary

no i mean a neutral pion

@peleus: didnt know bout the +/- actvity

cartman444

Decerto wrote: »

Transformer uses the fact that when mutual induction occurs, the new induced emf(voltage) depends on the number of coils in the secondary circuit compared to the number in the first, they use this to step up or step down voltage, more coils in 2nd circuit = bigger volatge/smaller current.

it is impossible to have 100% effecieny because due to the constant changing emf eddy currents are induced in the iron core changing electric energy to heat energy, there are other reasons like small losses due to sound energy and stuff aswell

why do people falling from a big distance to earth reach a terminal velocity?

a person falling to earth reaches terminal velocity when the force of gravity is equal to the force of the air resistance,

how does a nuclear generator work?

acidstorm

cartman444 wrote: »

how does a nuclear generator work?

It works by bombarding plutonium or Uranium rods with slower moving neutrons ( which in turn release their own neutrons) . The heat energy generated is then used to generate steam which might then be used to turn a turbine.

Experiment to show Total Internal Reflection??

Decerto

a neutron is shot into uranium 238 which are put in as fuel rods, which cause the nucleus of the uranium atoms to break up releasing 2 more neutrons, 2 smaller nuclei and energy in the form of heat and kinetic energy of the neutrons. the energy which is released as heat which is taken away by a coolant under pressure and used to power turbines when it changes to a gas. The released neutrons are slowed down using a moderater usually heavy water or graphite to produce further fission. The rate of the reaction is controlled by control rods.

What is an emission spectrum and why is it usefull

acidstorm

Decerto wrote: »

What is an emission spectrum and why is it usefull

An emission spectrum is a pattern of bright and dark bands obtained when a substance eg gas is heated or a high current is passed through it.

It is useful because all elements have different energy levels, and the bands present ( which represent the energy jumps) vary among the elements hence, can be used to identify substances.

Experiment to Investigate Lenz law?

Peleus

salman85 wrote: »

page in real physics?

it clearly says charge of pion is +2/3 + 1/3

pg 377

ken_cleary wrote: »

@peleus: didnt know bout the +/- actvity

Don't worry guys, only joking

Peleus

acidstorm wrote: »

An emission spectrum is a pattern of bright and dark bands obtained when a substance eg gas is heated or a high current is passed through it.

It is useful because all elements have different energy levels, and the bands present ( which represent the energy jumps) vary among the elements hence, can be used to identify substances.

Experiment to Investigate Lenz law?

Hang a loop from a retort stand.
Get magnet and put it through the loop.
The loop moves aways from magnet (opposing the change producing the current in the loop)

Pull the magnet out of the loop and the loop moves towards the magnet. (opposing the change producing the current in the loop but since the loop is on a string when it tried to oppose the magnet, it moves towards it <newton's 2nd>)

that's Lenz's law


What is a Neutrino? In what type of decay is this particle important? And Why????

acidstorm

Peleus wrote: »

What is a Neutrino? In what type of decay is this particle important? And Why????

A neutrino ( meaning little neutral one) is a massless, chargeless particle that is produced in Beta Decay. Proposed by Pauli to explain why momentum did not seem to be conserved in Beta decay.

GOOD LUCK 2MORO EVERY1

irishbucsfan

Good Luck tomorrow everyone.

The quoz is officially over, congrats I think you all did well. Results will be posted immediately following that other exam thing which I'm led to believe might be coming up tomorrow.

starkinter

Thanks for the quoz, irishbucsfan.

Peleus

quoz