# Search results

• Users: WY
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1. ### Induced EMF

oh i see now! sorry - I wasn't thinking properly! Thanks again :)
2. ### Induced EMF

thanks for the quick reply - but i don't quite understand how this ties in with finding the emf using the change in flux over the change in time.
3. ### Induced EMF

Hey I'm wondering if someone can help me out with this question. Q: In order to measure the magnetic fields produced by the power lines carrying 50Hz alternating current, a coil consisting of 1500 turns of area 5cm^2 as constructed. Suppose that there is a single power line carrying a...
4. ### Independent random variables

Thanks for the help! when i originally did it i used (88-10)/7 to try and standardise it - giving me a ridiculous number. So with the normal distribution N(10,7) what should I now do with those - I'm still kind of confused...
5. ### Independent random variables

Hi I'm wondering if someone can help me out on this question as to how to go about doing it: X_1, X_2... X_7 are independent random variables represnting a random sample of size 7 from the normal N(10, 7) distribution. Find to 3 dp probablitity that the sample total exceeds 88. I tried to...
6. ### Pressure in a glass bottle

Hi, I have been looking at some discussion questions in a textbook and there is a question about blood transfusion from inverted glass bottle rather than a flexible bag. The question" What would happen if blood were transfused from an inverted glass bottle rather than a flexible bag? I...
7. ### Density constant

Hey I am completely stumped as to how to find the density in this following question so I can answer part (c) Q: At a bottling plant soft drink flows in a pipe at a rate that would fill 200 375mL cans per minute. At point 1 in the pupe the gauge pressure is 152 kPa and the crossectional area...
8. ### Application of partial derivatives

Hey, I have no idea where to start, for this question. I know that I will probably have to use vector and scalar product and use the trig identity tan^2(theta)=sec^2(theta)-1 - and of course partial derivatives Question: In order to determine the angle theta which a sloping plane ceiling...
9. ### Application of partial derivatives

Hey, I have no idea where to start, for this question. I know that I will probably have to use vector and scalar product and use the trig identity tan^2(theta)=sec^2(theta)-1. Question: In order to determine the angle theta which a sloping plane ceiling makes with the horizontal floor...
10. ### If Ax = 0 has one solution, show m>=n

Thanks for replying :) But I'm not to sure what you mean - i don't think i am very familiar with that theorem... could you elaborate a little? hehehe
11. ### If Ax = 0 has one solution, show m>=n

Hey I'm not to sure on how to approach this problem - I think I have to use induction but I don't know where to start! Question: Let A be an mxn matric. Suppose that Ax=0 has only one solution, namely x=0. Show that m >= n Thanks for the help in advance
12. ### Varying densities and wave propogation

hey I was just wondering what would happen if you had a length of string with varying densitities with one end fixed to a wall and you sending a pulse down it. Would the waves travel faster along some bits or change amplitude at all or do something i haven't mentioned? Can anyone enlighten...
13. ### Vertical SHM

a multiple of the amplitude - so would i have to divide it by 2 to find the amplitude?
14. ### Vertical SHM

Hi I'm attempting this question and I'm wondering if this is the correct way of going about it or if I'm completely off track: For lunch you and your friends decide to stop at the nearest deli and have a sandwich made fresh for you with 0.300 kg of Italian ham. The slices of ham are weighed on...
15. ### Gas expansion

oh I see! thanks for clearing that up now - its all crystal clear now!
16. ### Gas expansion

Thanks for replying! Sorry I wrote down the wrong equation -_- but in this problem doesn't the volume of gas change? So why doesn't it effect the way we caluclate it?
17. ### Gas expansion

Hey - I'm doing this question (see below) but I don't hav a clue where to start! A flask with a volume of V, provided with a stopcock, contains ethane gas at a temperature of T_0 and atmospheric pressure p_0. The molar mass of ethane is M. The system is warmed to a temperature of T, with the...
18. ### Heat transfer and friction

Hey that does make sense thanks! But when I tried doing that -since i got W_f=-1630 I would calculate that -1630 = 31x3800xdeltaT which would be -0.0138 - but this is wrong - have i missed out using a formula? or substituted in the wrong numbers?
19. ### Heat transfer and friction

hey I'm wondering if someone can help un-stuck me on this question - I'm not sure if what I'm diong is right >< A crate of fruit with a mass of 31.0kg and a specific heat capacity of 3800 J/kg K slides down a ramp inclined at an angle of 38.4 below the horizontal. The ramp has a length of...
20. ### Angular velocity of a block of mass

hahah right thanks for that!
21. ### Angular velocity of a block of mass

Hey I was doing a question and I need someone to check if my method is ok - or stop me if I'm on completely the wrong track! A block of mass m is attached (with a massless string) to a wheel. Consider the bicycle wheel is not turning initially. The block is allowed to fall a distance of...
22. ### Centre of mass - is this right?

Hey thanks for that! That makes much more sense now!
23. ### Centre of mass - is this right?

Hello I was given a question of 2 masses m_a and m_b whos centres of L distance apart and are connected by a massless rod (so it kind of looks like a dumb-bell). Each ball through its centre has an axis perpendicular to the rod (axiz a and b respectively) and each has a moment of inertia...
24. ### Conservation of energy for toy gun

I've been reading about a situation on the conservation of energy: A spring-loaded toy gun is used to shoot a ball of mass m straight up in the air. View Figure The spring has spring constant k. If the spring is compressed a distance x_0 from its equilibrium position and then released, the...
25. ### Falling masses

O I feel like such an idiot... I missed the most obvious things! Thanks for the hints guys!
26. ### Falling masses

I have been mulling over this question for ages and I just don't know where to start! Question: Two blocks with different mass are attached to either end of a light rope that passes over a light, frictionless pulley that is suspended from the ceiling. The masses are released from rest, and the...
27. ### Conservation of momentum and isolated systems

Thanks you! Thanks to everyone for your help in making this so much clearer to me!
28. ### Conservation of momentum and isolated systems

I was reading on the conservation of momentum and they mention how in isolated systems momentum is always conserved and if the external forces of the system is zero. In the case of friction or drag acting against the motion of a body would that be considered as part of the isolated system or an...