# Recent content by uniidiot

1. ### Three levels laser

Well surely the energy needed to excite the electrons to the 3rd level, is equal to the energy released as they drop back down to the 1st??
2. ### Sketch the curves y =|x| and y = 2 - x^2 on the graphs

ok, but how?? :S
3. ### Sketch the curves y =|x| and y = 2 - x^2 on the graphs

is that what its asking? if so how do i work that out, is it similar to the wa you work out whether a curve crosses the x-axis. thanks
4. ### Sketch the curves y =|x| and y = 2 - x^2 on the graphs

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...
5. ### Gas Laws

oh ok, so does that mean that the number of moles in 200g of CO2 is 0.2 (kg) / (6.02 x 10^32) all x 3 becuase there are 3 moles per molecule
6. ### Point charge and electric potential

thank you. i think it was a typing error lol.
7. ### Point charge and electric potential

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 =...
8. ### Gas Laws

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
9. ### Gas Laws

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!
10. ### Gas Laws

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...
11. ### Polar and cartesian form

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.
12. ### Polar and cartesian form

ok thanks, when doing cos(theta) woud theta be in radians or degrees?? thanks
13. ### Polar and cartesian form

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...
14. ### Stupid question

thankyou! and yes a) was suposed to be \overline{z} lol
15. ### Stupid question

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