Physics Pop Quiz

Shox

Rule of thumb:Is this the same as the right hand grip rule??

carlowboy

Shox wrote:

refraction of light
1)The angle of incidence, the angle of refraction and the point of incidence on the normal all lie on the same plane
2)The sine of the angle of incidence over the sine of the angle of refraction equals a constant

Give another name for the second Law above???

Dlí Snell.


Give two industrial uses of X Rays.

JC 2K3

Shox wrote:

Explain terminal velocity with regards a person jumping out of a plane?

Friction is a force that opposes motion.

When jumping out of a plane, friction from the air opposes the motion of you falling.

The friction force increases as you accellerate downwards.

When the friction force equals the force of gravity acting on you, your velocity becomes constant, this is called terminal velocity.

Explain the doppler effect.

ninebeanrows

Explain the differences between forward and reverse bias.

The Filth

Joules Law: . . . .damn i remembered it 2 secs ago but its gone again now.. dis beta not happen on mon

Yeah i could never remember it until now:
P=I^2R think thats how u say it anyway
p is equal to i squared r anyway
where p is rate of energy loss by conductor, i is the current and r is the resistance

2)The sine of the angle of incidence over the sine of the angle of refraction equals a constant

Give another name for the second Law above???

Refractive index

Q: explain how snells window comes about in relation to a diver looking up from beneath the surface of water

carlowboy

JC 2K3 wrote:

Explain the doppler effect.

Séard is dlí doppler ann ná an athrú sa minicíocht dealraithe agus é ag gluaiseacht i dtreo nó ón féachadóir.
Definition do or or are you thinking more, because its hard to explain without diagrams?


Who discovered the X Ray?

carlowboy

The Filth wrote:

Yeah i could never remember it until now:
P=I^2R think thats how u say it p is equal to i square r anyway where p is rate of energy loss by conductor, i is the current and r is the resistance



Refractive index

Q: explain how snells window comes about in relation to a diver looking up from beneath the surface of water

Pretty sure he means snells law, not refractive index to be precise.

The Filth

Who discovered the X Ray?

William Roentgen methink,

Q: How is the production of x rays the inverse of the photoelectric a effect?

Pretty sure he means snells law, not refractive index to be precise.

Hopefully they wont be that scabby

JC 2K3

carlowboy wrote:

Séard is dlí doppler ann ná an athrú sa minicíocht dealraithe agus é ag gluaiseacht i dtreo nó ón féachadóir.
Definition do or or are you thinking more, because its hard to explain without diagrams?

meh

It's "iarmhairt", in any case.

carlowboy

JC 2K3 wrote:

meh

It's "iarmhairt", in any case.

I know, I know, I forgot myself

carlowboy

The Filth wrote:

William Roentgen methink,

Q: How is the production of x rays the inverse of the photoelectric a effect?

X rays are photons emitted due to bombardment of electrons whereas photolectric is the emission of electrons from bombardment of "photons". That too simplistic?

Describe Cockroft and Walton's experiment.

madnirvana

GIve TWO uses of:-

Photoelectric effect

Gamma Rays

Dopler effect

U.V rays

Infra-Red

Diode

Tricky?

nedward

ec18 wrote:

its heavy water not hard water.....deuterium for the control rod

Deuterium is heavy water....

EDIT On a side note, is Cockroft and Waltons' experiment the first artificial transmutation of a nucleus, because I thought Rutherford changed N into O? Yes? God bless teachers. My teacher thinks they won the Nobel Peace Prize, as well as the above question.

Turnip2000

GIve TWO uses of:-

Photoelectric effect = automated counters, Security beams(Like in the movies)

Gamma Rays

Dopler effect = Making cars sound cool

U.V rays

Infra-Red = Security cameras

Diode =

O MY! im in trouble arnt I!!

nedward

madnirvana wrote:

GIve TWO uses of:-

Photoelectric effect-Burglar alarms, counting items on a conveyor belt.

Gamma Rays-Irradiating food to preserve it, killing cancer cells.

Dopler effect-Gardai speed guns, red shift.

U.V rays-tanning salons, used in crime scenes to see traces of blood (a la the Da Vinci Code)

Infra-Red-IR goggles to see in the dark, thermal imaging

Diode-Those light thingies on the telly, circuits activated by light?

Tricky?



Tell me all about Bohr's model of the atom.

The Filth

Cocroft and waltons exp:-
They accelerated hydrogen protons from a hydrogen discharge tube using a particle accelerator, which is essentially an evacuated tube which has high voltage across it,
These protons struck a lithium target, placed in the tube at 45 degrees, this collision produced 2 alpha particles which were emitted either side of the tube, they were seen as scintillations on a zinc sulphide screen using a microscope

The reaction: H1,1 + Li7,3 = He4,2 +He4,2 + energy
Anyfink else?

Anyway Q: Why do you wait a few minutes in the experiment to verify boyles law before increasing the pressure?

The Filth

Bohrs model of the atom:
The electrons on an atom are arranged in shells, each of the electrons in these shells have a specific energy, when the electrons get more energy ie get excited they jump out to another shell,
After a very short time they emit a photon which is equal in energy to the energy the electron absorbed originally, they then fall back to their original shell as they have the same energy they began with

Energy of photon emitted = energy of higher shell - energy of lower

Q How does particle pair production occur, describe it...

Fobia

nedward wrote:

Dopler effect-Gardai speed guns, red shift.

Red shift is hardly a "use"..

Turnip2000

Fobia wrote:

Red shift is hardly a "use"..

I only red about it the other day but i think it is?? Its USED to determine how far away a star is?

ApeXaviour

The Filth wrote:

Q How does particle pair production occur, describe it...

When a photon of strikes a nucleus, a particle and its anti particle are created (electron-positron). The incident photon needs to be at least of the same energy as the combined rest mass energy of the two created particles. Momentum is conserved.

Define the volt, and what are its units? (I know they're the volt but what are the units that make this up)

genericgoon

Do you mean voltage?ie the potential difference? Thats the work done in bringing charge from one point to another. a volt is where one joule is used to bring one coulomb from one point to another.

Qt: what are the laws of electromagnetic induction and state what they say.

Feddd

Turnip2000 wrote:

I only red about it the other day but i think it is?? Its USED to determine how far away a star is?

Its a use involved in astromony to determain the movement of start/planets but what the poster before you eamnt is that you would need to elaborate on it rather then say "Red shift".
It would be like saying BABYS is a use for ultrasounds(Pregnancy scans).

microbiek

The Filth wrote:

Cocroft and waltons exp:-
They accelerated hydrogen protons from a hydrogen discharge tube using a particle accelerator, which is essentially an evacuated tube which has high voltage across it,
These protons struck a lithium target, placed in the tube at 45 degrees, this collision produced 2 alpha particles which were emitted either side of the tube, they were seen as scintillations on a zinc sulphide screen using a microscope

The reaction: H1,1 + Li7,3 = He4,2 +He4,2 + energy
Anyfink else?

Anyway Q: Why do you wait a few minutes in the experiment to verify boyles law before increasing the pressure?

A:To keep temperature constant



Q: Explain Intrinsic Conduction.......(Semiconductors)

madnirvana

microbiek wrote:

A:To keep temperature constant



Q: Explain Intrinsic Conduction.......(Semiconductors)

conduction in a pure semi conductor due to elec moving from negative to + and equal amount of hole moving in opposite direc.

Anyone knows what method you have to learn for the Exp- To measure velocity

Is it Ticker tape one or Light gates?

Nehpets

you can do either

microbiek

is static electricity in applied electricity or the core???

Nehpets

normal elec

microbiek

Nehpets wrote:

normal elec

really!!! is it big or just a sts........like the thing in the chimney and aircraft refueling etc???

JC 2K3

A whole chapter.... how did you miss that?

Fobia

Actually, sorry for being off-topic, but I have a similar question. On the monochromatic light exps, does one need to know both or are you guaranteed to be able to do either (Ie, spectrometer or laser method)?