1. Homework Statement
A new drug is in trial, and it is found that the drug will cause adverse effects on some patient.
5% will have diarrhoea and 3% develop a rash after taking the drug. Also, 7% of patient have either diarrhoea, rash or both after taking the drug. Need to find the...
the following data apply to the speaker system:
coil diameter = 5.8cm
coil turns = 86
coil and cone mass = 30g
magnetic flux density = 0.12T
Current in the coil = 1.8A
Using the above data, the acceleration of the cone will be?
A) 12.6 b) 79.3 c) 113 d) 247
This comes from my revision sheet i...
Re: rusting
the cathode nail takes 25mins to gain 2.36 -> 2.4. This is not too accurate becuase there are those (green stuff?) form around the nail and when i pull the nail out and measure the weight those green stuff fall out and stay in solution.
solution is HCl
the rust on cathode...
Re: rusting
well yes when the nail form rust it is heavier but im not sure about the cathode (rusted iron) will gain or lose weight. I re-tested again at school day and still got the same result. So my question is how come the nail rust it gains weight, and when the nail being de-rusted it...
Re: rusting
well the h2o will have impurities, and the nail is actually steel and iron?
As part of the experiment i am also to de rust the nail.
would the nail suppose the gain weigh after electrolysis? Because when the nail rust it gains weigh, and if de rust will it lose weigh? but my nail...
So i did an experiment and pu tiron nail into water and serveral days later it starts to rust.
and i looked at the book and the chemical process is
1)Fe loses electron
2) that electron + oxygen + water produces hydroxide
3) hydroxide and Fe ion reacts and form Fe(OH)2, green rust
4)...
hello, I am not too sure of how charged particle got to do with magnetism.
"Magnetism is a force of attraction or replusion that acts at a distance. It is due to a magnetic field, which is caused by moving electrically charged particles or is inherent in magnetic objects such as a magnet."...
1. Homework Statement
Find the first, second, third, fourth, fifth derivatives of the function y = sin 3x.
Find a rule that can help to find the 50th derivative of the function.
It's urgent!
2. Homework Equations
y= sin x y= cos x
y' = cos x...
1. Homework Statement
solve below using de Moivre's theorem, in polar form
z^3 = i
2. Homework Equations
r CIS theta
Answer:CIS pi/6, CIS 5pi/6, CIS (-pi/6)
3. The Attempt at a Solution
r^3 = sqrt(0^2+1^2)
r^3 = sqrt (1)
r = sqrt (1)
no idea how to get the angle
why does the increase of sound frequency will decrease the penetration depth?
how can this related to diffraction of sound?? Is it because they can be easily reflected??
need answer desperately, thx
hey here is another question :S
When the frequency of the wave is too high it will be absorbed easily? I don't understand why. Is it because of the increase in wavelength?
yes it calculates the time that takes to travel back to the transducer to produce an image.
but i dont really get this staement below "the crystal will be changed in the same way as when crystal the crystal was generating ultrasound. In this case the changing crystal will cause a changing...
So when this happens this is the reverse of the piezoelectric effect? (from mechanical energy to electrical energy.)
And the transducer receives sound wave because of this reverse piezoelectric effect?
also there is the other bit that i dont understand
"the crystal will be changed in the same...
how does ultrasound machine detects the reflected wave?
i have read a bit of information and unfortunately Im still unsure how they detect the wave.
"The rapid shape changes, or vibrations, of the crystals produce sound waves that travel outward. Conversely, when sound or pressure waves...
1. Homework Statement
f(x) = ((x^2+2)^2)/(x+2)^1/2
Use the chain rule to find the derivative
2. Homework Equations
None
3. The Attempt at a Solution
((x^2+2)^2)(x+2)^-1/2
PS: Answer in the book is 3x((x^2+2)^1/2)
I have no idea how they get it there, would like some help, thx!
1. Homework Statement
this is not a homework question... i want to know density vs resistance
2. Homework Equations
R = ρl/a
3. The Attempt at a Solution
none so far
independent of x simply means that x^0 and yes I am trying to find the co-efficient there
heres are my working out.
independent of x in (6x^(2)-3/x)^6
1. (6^(6-r) x^(12-2r) ((-3^(r))/x^(r))
2. x^(12-2r)/x^(r) = x^(0)
3. x^(12-3r)=x^(0)
4. 12-3r=0
5. r = 4
how do i find the independent of x in (6x^(2)-3/x)^6
I know that the formula nCr a^(n-r) b^r
i have got an answer of n = 6 and r = 4 i just wanna make sure that im correct and i would like someone to give me a hand~ :)