Physics Pop Quiz

cocoa

measuring the angle isn't the problem, it's getting the angle big enough that is. I know it's possible because I have a nifty little glass block at home that achieves it. You look in the top and you see a stamp at the side, but look in the bottom and it's a mirror, guess why

edit: look in the side to see a mirror, not bottom ...

eZe^

JC 2K3 wrote:

I presume you just measure the angle differently? Like, the angle you shine the ray at the block at would not be C, but you could get C from that...

You see, when you change the ray box, it isnt entering normally anymore, so refraction happens all over the shop, making it nearly impossible to work. I cant quite explain it properly but if you ever try it itll be clear.

carlowboy

I never learned those formulae using calculus.....

eZe^

carlowboy wrote:

a= rate of change of velocity so
a v/t-u/t
at=v-u
v=u +at

v= u +at
square both sides
v^2= u^2 +2uat+(at)^2
.....= u^2 +2a(ut +at^2/2)
v^2= u^2 +2as

Is mine too simplistic?

No, its actually more complicated if you look... We were just flaunting the applied math way.. ahaha.

JC 2K3

But if you had a really long glass block.....

eZe^

JC 2K3 wrote:

But if you had a really long glass block.....

Hahah, I resorted to unrealistic things like that too, I was arguing about using loads of randomly shaped blocks until one is the right design! ahahah

carlowboy

eZe^ wrote:

No, its actually more complicated if you look... We were just flaunting the applied math way.. ahaha.

I did app maths for a while but sadly once a week with one of the worst teachers in the country doesn't help.

cocoa

eZe^ wrote:

Hahah, I resorted to unrealistic things like that too, I was arguing about using loads of randomly shaped blocks until one is the right design! ahahah

not necessary, a square one works just fine, I have one in front of me...

JC 2K3

A really long one or one with a high refractive index?

EDIT: Considering you said square, I'm guessing one with a high refractive index.

eZe^

carlowboy wrote:

I did app maths for a while but sadly once a week with one of the worst teachers in the country doesn't help.

I started in towards the end of August this year on my own, its not that bad man! Although now its too little too late!!

a = dv/dt
a dt = dv
a Int dt = Int dv (since a is constant because its constant accelerated motion equations)
at + c = v
when t = 0, v = u
u = c
therefore v = u + at..

The others are just derived from that, and you know the other method, so it really makes no difference.

cocoa

JC 2K3 wrote:

A really long one or one with a high refractive index?

EDIT: Considering you said square, I'm guessing one with a high refractive index.

bingo

sternn

Since this has veared away from questions, i'll start it up again.

Q: What is the function of a control rod and state the material it can be made of?

madnirvana

sternn wrote:

Since this has veared away from questions, i'll start it up again.

Q: What is the function of a control rod and state the material it can be made of?

it slows down the high speed neutrons so they wont be absorbed by uranium 99% one.. what is it called?? 238?

hard water or cadmium

.................................

WHAt the difference between Photoemission and photoelectric effect?

ZorbaTehZ

A control rod is a neutron absorber, and they are used to control the rate of fission in a reactor and hence the energy levels in the reactor. Example of a material that can be used is Cadmium.

Q: Name the man who discovered the Neutron, and briefly describe the experiment that he used to do so.

EDIT: Ambiguity

Raphael

Actually the control rod completely absorbs all neutrons to prevent any reaction, and is made of cadmium. The moderator slows the neutrons, and is hard water.

madnirvana

Raphael wrote:

Actually the control rod completely absorbs all neutrons to prevent any reaction, and is made of cadmium. The moderator slows the neutrons, and is hard water.

yeah thats right:o

i need to revise.

Chadwick discovered neutrons but thats in chemistry course.

Alpha particles hit beryllium and neutrons were emitted..


Q- WHAt the difference between Photoemission and photoelectric effect?

microbiek

madnirvana wrote:

yeah thats right:o

i need to revise.

Chadwick discovered neutrons but thats in chemistry course.

Alpha particles hit beryllium and neutrons were emitted..


Q- WHAt the difference between Photoemission and photoelectric effect?

photoelectric is emissio of electrons due light of certain frequency falling on the metal large enuf so that the electrn can overcum d workfunction duno d otha

nedward

The photoelectric effect is the emission of electrons from the surface of a metal due to electromagnetic radiation of a suitable frequency falling upon it.

Photoemission is the emission of electrons (a current) from the cathode due to light falling upon it. Dunno the difference.

Give three functions of X-rays.

Turnip2000

nedward wrote:

The photoelectric effect is the emission of electrons from the surface of a metal due to electromagnetic radiation of a suitable frequency falling upon it.

Photoemission is the emission of electrons (a current) from the cathode due to light falling upon it. Dunno the difference.

Give three functions of X-rays.

Medical(kill cancerous cells + See breaks in bones) , Industrial(Check for internal flaws in piece) ,

What is specific latent heat?

The Filth

1) Medical imaging
2) Industry- checking thickness of products...
3) Security imaging

Give an expression for the period of a satelite around a planet due to gravity...
(You know the one im talking bout, cant remember wording of q)

The Filth

Slh= the ammount of heat energy needed to change the state of 1kg of a substance without a change in temperature of that substance.

Whats hookes law?

Turnip2000

The Filth wrote:

Slh= the ammount of heat energy needed to change the state of 1kg of a substance without a change in temperature of that substance.

Whats hookes law?

F = -KS

K=constant S= Displacement

What is Archimedes principle?

Shox

Hookes Law: When an object is bent stretched or compressed by a displacement 2, the restoring force is proportional to the displacement provided the elastic limit is not exceeded..

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

Shox

Archimedes principle: for a body partially or fully immersed in a liquid the upthrust is equal to the weight of the displaced liquid

ec18

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

The Filth

Archimides principle - when a body is wholly or partially immersed in a liquid it experiences an upthrust equal to the weight of the liquid it displaced...

Define joule's law

Shox

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

The Filth

Terminal velocity man falling from plane...
When an object falls from a plane it will accelerate initially at the maximum value of acceleration due to gravity
However due to newtons 3rd law- the air will exert an equal but opposite force on the object, ie air resistance
When the force of gravity and the force of air resistance are equal the acceleration will be zero and this is terminal velocity, the object continues to fall at this velocity until it reaches the ground....

State the laws of refraction of light

ninebeanrows

Q. What is the rule of thumb?

Shox

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???