I am revising for my A levels and I have noticed that a common question on the paper is to define RESISTIVITY.
I have looked and looked but found no definitive description or a good definition.
I know the formula but is it right to just say that "resistivity is directly proportional to a...
Just wondering if anyone can check over my answer for a question.
Q) A 1.7kg object is swung on the end of a 0.6m string in a vertical circle. The object does one revolution every 1.1s. What is the tension in the string at the top of the circle? and the bottom?
A) m=1.79kg r=0.6m...
just a check of my work please.
I have to write an expression for the nth term of this geometric sequence.
a1=100
a2=106
a3=112.36
I've worked out the ratio to be r=1.06
I am using the formula un=ar(n-1)
so the expression i have come up with is un=100(1.06)(n-1)
Is this correct? I have...
Just a check of my work please,
The topic is series and sequence,
Question:
The sequence u1, u2, u3,..... where u1 is defined by u1=2 and Un+1 =un+4
Find the nth term, un, of the sequence.
I got the answer,
u1=-1
u2=-1+4= 3
u3= 3+4 = 7
So:
un = 4(n-1)-1
This seems to work but not sure if...
Hi guys,
Having trouble with a question
I need to know the displacment of a point on a spring at certain times.
At t=0 point p is at its maximum displacement at 2cm
point A is further down the spring at p-A = 0.4m
A transverse wave of frequency 5Hz is moving along the spring at...
simultaneous polynominals!!
stuck on this coursework question
The cubic polynominal f(x)= 4x^3+ax^2+bx+6 has a factor (x-2)
when it is divided by (x+1) it has a remainder 0f -15
find the values of a and b
I did as follows
factor (x-2)
f(-2)
4(-2)^3+a(-2)^2+b(-2)+6=0
equals 4a-2b=26...
I have been asked to draw the graph of the function f(x)= (x+3)/(x-2)
I have found where it cuts the y axis by putting x=0 but am unsure of how to find the x value.
I found the inverse of f(x)= (x+3)/(x-2) which gave me x= (y+3)/(y-2) then set y=0 which again gave me x=-3
I have checked...
Im looking for g(f(5))
where f(x) = X^2 - 3x
and g(x) = 8 + 2x - x^2 xER and x is greater than or equal to 1
I have first found f(5)
(5)^2-3(5)
which equals 10
However when i do g(10)
8+2(10)-(10)^2
that gives me a negative number of -72!! Which cant be...
Just want to check that i am doing this question correctly.
f(x) = 2x+5 h(x) = 1/x , x \neq0
Find the inverse of fh(x)
So first i found the function fh(x)
2*1/x+5
then let y = 2*1/x+5 , x \neq0
now this is the bit i cant rememeber how to do, when i try and make...
motion in a straight line....tough one
ok, a cyclist is travelling at 10ms^-1. he sees trafic lights ahead at 108m. He carries on cycling for a time T before decelerating and stopping at the lights 16.7seconds after he first saw the lights.
Calculate T
Im a bit stuck because i feel this...
Homework Statement
ok the question is as follows. A pilot flying at 45m/s is trying to bomb a target on the ground 15m in diameter. he is at a height of 98m
(a)how long does it tke for the bomb to hit the ground?
(b)at what horizontal distance does the pilot have to be to release the bomb...
ok im trying to find out how to work out the intial velocity of a projectile dropped from a height h and reaches a distance s.
say a ball thrown from a height of 2.8 metres and reaches a distance of 3 metres.
I want to be able to work it out WITHOUT having to work out the time.
so cant...
A positivley charged particle is travelling in a straight line with velocity v at a small angle from the horizontal.
At a certain instant a constant uniform electrical field is applied in the downward vertical.
what is the direction of the charged particle?
I figured that the equation for a...
ok revision question fo me, just wanna check my reasonning.
which of te bulbs on the circuit of the attatched file will shine more brightly?
i think p.............because s and t r and q are in parrellel which is resistance 1/Rs+Rt+1/Rr+Rq
where Rp is the sum of the resistance of...
a sample of an idel monotomic gas is intially at a pressure 1.6*10^4Pa and undergoes an adiabatic compression which halves the volume. What is the final pressure?
ive been trying to find a way of useing the equation W=-P\DeltaV but am starting to think this is the wrong one as i cant see...
Quick question, if i had a circuit of 5 light bulbs whereby 4 were running parellel in a sequence and one was running seperatly, would one be brighter than the others?
sorry if it is hard to visulise :)
can anyone tell me how i should approach this problem
calculate the number of molecules of air in a beach ball of volume 6.0*10^-2m^3. The air is at temperature 35degrees, a pressure of 1.1*10^5Pa and can be trested as an ideal gas.
i just want to know what area of classical physics it is
Ok just a quick question
trying to work out the orbital period of an asteroid around the sun which has an orbital period 4times that of the earth which is 1.5*10^11m
i worked out the radius of the asteroid to be 6*10^11 but cant find the equation for the orbital period.
Does anyone know it...
ok just want a check of my work before i send it :)
differntiate the function;
f(x)=\frac{x(20-x)}{36}
so,
f'(x)=\frac{(20x-x^2)}{36}
f'(x)=\frac{(20-2x)}{36}
f'(x)=\frac{(10-2x)}{18}
Then....use the composite rule and your answer above to differntiate the function...
Does anyone know how to derive a fraction?
I want to be able to differentiate f(x)=\frac{x(20-x)}{36}
Ill show you what ive done but think ive just simplified it.
f(x)=\frac{x(20-x)}{36}
f(x)=\frac{(20-x-x)}{36}
f(x)=\frac{(10-x)}{18}
Is this correct?...........although not...
drawing graph of functions...HELP!!
ok, i am going to admit i am TERRIBLE when it comes to drawing graphs of functions. I have no idea what i am doing and kind of need a step by step approach. I really want to learn the best way of doing this as its now a big obstacle in my course.
The...
A large flat disk with moment of inertia I is spinning with angular speed 18 rad/s
a small object lands on the disk and changes the moment of inertia to 1.5I
what is the new speed?
i used L=I\omega to give me 18*1.5=27 rad/s
i used this because L is the angular momentum of the disk and...
This is a revision question for a test ive got. Just want to check my answer.
An asteroid with mass of 1.8*1015kg and radius of 6.7km attracts a spacecraft that has come into its gravitational influence. What speed will the spcaecraft crash into the surface. intial speed of spacecraft is...
sounds simple, im however stuck
A planet has a thin isothermal atmosphere at a temperature of 320K and is composed entirely of methane (relative molecular mass of 16)
The acceleration due to gravity at the surface is 8.3 m/s/s
calcualte the height of the atmosphere.
not realy sure where...
This is just a revision question for an exam i have in a couple weeks.
I think i kow the answer but just want to double check.
a curling stone is released with an instial speed of 3.1 m/s
the coefficent of sliding friction between the stone and ice is 0.017
What is the distance the stone...
Hi there,
im having trouble finding the right equation for a problem ive got.
I have a point charge with an equipotential of 40v at 0.4cm. I am suppossed to work out the value of the charge.
Ive tried
q/4\pi\epsilonr
but it doesnt work and i think its because im not putting in a...
my question is.......... the semimajor axis of the orbit of jupiter is 7.8*108.
If an asteroid has an orbital period half of that of jupiter what is the semi major axis?
All i did was times 7.8*108 by 1/2 and got 3.9*108.
Seems to simple!!??
any comments much appreciated
my question is.......... the semimajor axis of the orbit of jupiter is 7.8*108.
If an asteroid has an orbital period half of that of jupiter what is the semi major axis?
All i did was times 7.8*108 by 1/2 and got 3.9*108.
Seems to simple!!??
any comments much appreciated
im looking for the 3 principals i need to be employ in determining the electronic structure of the ground state of an atom
Ive got Paulis exclusion principle where no 2 electrons in an atom can occupy the same quantum state and hunds rule of the total spin of the electrons always has it...