1. Homework Statement
Sketch on the same axis the graphs of y = |x| and y = 2 - x^2.
For which values f x is the inequality |x| < 2 - x^2
2. Homework Equations
3. The Attempt at a Solution
I don't really understand what it is asking me to do, i've sketched the two curves...
1. Homework Statement
three point charges, each of 10^-9 are located at 3 corners of a square of side 20cm. Calculate the electric potential at the forth corner.
2. Homework Equations
V = Q / (4(pi)(epsilon 0) r)
3. The Attempt at a Solution
Potential because of corner A =...
ok scrap that last post lol,
1 mole of carbon-12 is 12 grams,
1 mole of oxgen-16 is 16 grams,
so i still need to know how much of the 200g is carbon.
thanks
ok well the ratio of CO2 is
12:32
one mole of C is 6.02x10^23 x 12
one mole of O is 6.03x10^23 x 16
but how do i work out how much of the 200g is carbon?
thanks so far!
1. Homework Statement
A 200g sample of CO2 occupies a volume of 110 L at a pressure of 1 atm.
a) What is the number of moles in the gas
b) What is the temperature?
c) if the volume is increased up to 200 L and the temperature is kept constant. what is the new pressure.
2...
I just tried to sketch the curve whos form is r = cos(theta)
but there is not curve!!??
when theta = 0, r = 1
when theta = (pi/2), r = 0
when theta = (pi), r = -1
ect
so there is no curve!!! the point im finding are just on the x or y axis, or on the origin!
am i doing something wrong.
1. Homework Statement
i) Express the equation r = 1 + cos(theta) in Cartesian form.
ii) Sketch the curve whose equation in polar form is r = cos(theta)
2. Homework Equations
x = r cos (theta)
y = r sin (theta)
3. The Attempt at a Solution
i) x = r cos (theta) = (1 + cos(theta)) cos...
this will probably seem like a really stupid question but here goes.
If z = 3 + 2i find the following
i) z
ii) z x z(with a horizontal line above it)
iii) z^2
what does the horizontal bar mean, i can't find it in my reivsion books lol.
Thanks
Thanks for everyones help =)
but i still cant get the corect answer:
Q2 = ((F x r^2) / Q1) x (1/(4 x pi x epsilon 0))
Q2 = ((4.91x10^-4 x 3^2) / 10^-8) x (9x10^9) = 3.97x10^15
Above the question it is stated that
(1/(4 x pi x epsilon 0)) = 9x10^9
i still cant see how im not getting [ 4.9...
ah, stupid me!
so
Q2 = (1/(4 x pi x epsilon 0)) x ((Q1 x f) / r^2)
Q2 = (9 x 10^-9) x (((1.0 x 10^-8) x (4.9 x 10^-4)) / 3^2)
Q2 = 4.9 x 10^-3
i, getting closer but, the answer should be 4.9 x 10^-9
i thought it might be the units but they seem ok now
i see what i've done, it should be in Kg not g
so
F = 0.00005 x 9.8 = 4.91 x 10^-4
ok well:
F = x ((Q1 Q2) / r^2)
so if i rearrange to get Q2
Q2 = (1/(4 x pi x epsilon 0)) x (Q1 / (r^2 x F)
yes???
1. Homework Statement
The centre of a small sphere carrying a positive charge of 1.0 x 10^-8 C is fixed at 3cm above the centre of a small conducting ball, which had a negative charge and a mass of 0.05g. If the ball remains suspended, what charge does it have?
Answer is [ 4.9 x 10^-9]...
Ok i think i might have cracked the 1st bit now,
dh/dt = -kh
h = Ce^-kt
ln h = -kt + A
but i dont understand how to work out how long it will take to empty 1/2 of the water, there are no figures to work with?
thanks for your help so far neutrino.
the speed at which the height of the water decreases
well the diffrence of the height from the initial value is h - h0
so the rate of change is
dh / dt = (h - h0) / (t - t0)
?
1. Homework Statement
A tank is in a shape of a cylinder with a circular cross-section of area A. Initially the depth of water in the tank (the head) is h0. At time t = 0 water is allowed to leave the tank ffrom a valve at the bottom. The rate at which the water leaves the tank is...