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...
I'm pretty sure the lost volt is the resistance inside the battery. Once you work out the lost volt you can minus that from the voltage of the battery and work out the real value of V. Most questions dont include thw lost volt because it is quite small and considered negible. I think they are...
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...
I can now thanks :)
I see what you have done but im not sure why 1/x becomes 2/x in this circumstance. Im just trying to understand the mechanics behind it so i can be fully aware. If h(x) was 1/x + 5 would it still be 2/x +5 or 2/x + 10?
your correct in your assumption, my teacher is poor...
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...
The question actually says
2 cyclists (B) travelling at 9ms^-1 and (A) travelling at 10ms^-1 are at the same point when they see traffic lights 108m away. B travels at its speed for a furthe 6seconds before decelerating and stopping at the lights. A travels for a time T before decelerating and...
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...
the choices i have are
a) the particle stays on the same path,
b)the particle follows a circular path in an anticlockwise direction
c)the particle follows a circular path in a clockwise direction
d)the particle the particle follows a helical path in an anticlockwise direction
e)the particle...
sorry i didnt mean the grip rule just the right hand rule. i checked it again and figured that if the particle was travelling along the +x axis and the electric field was in the -y direction...the force on the particle would be giong into the page(so to speak) this would make it travel in an...