Recent content by Kawakaze

I am looking for a solvent that can dissolve photo setting resin after it has been hardened. I think it is Diazo resin or something like it. Can anyone suggest something? Thanks!

Thanks for the reply. But, wouldn't this only occur if we had one eye closed? I do like this idea though, it is very unlikely, which explains why in 30 years it hasn't happened before. Yet it should be possible to replicate the effect.

I am a bit wary about posting this, as I am pretty sure what the response would be if I claimed this was paranormal or some other weird stuff. So before we start, I do not believe in ghosts, I do not follow religion, I am very much a believer in the scientific method. I am not claiming to have...

Well, I am guessing cylindrical coordinates would make the easiest calculations. But I really suck at the conversion.

I came across this question on a past paper and would appreciate some help. It is too hard for me at the minute. The problem - The volume of a body whose surface is formed on the underside by the paraboloid z = x2 + y2 and bounded on top by the cone z = 3-2(x2 +y2) (a) Explain which...

Thanks! One last question if I may, what is the significance of the integration constant that appears when integrating the velocity vector to get the position vector, and where does it appear in your solution. Cheers!

Azizlwl, thanks for the reply, but can you explain it a little more in depth please, i don't understand what your symbols mean, especially the z. Is U initial velocity?

I know this is what i need to do, is there any worked examples online you know of? Also still no idea about part (a)

Thanks for the reply Muphrid. I made some progress thanks to your suggestion. I have an expression for the position vector. First problem is I don't know if they want a numerical or algebraic answer. r=4t√g cos(α)i + (4t√g sin(α)-1/2 gt2)j + C I need to get find the integration constant...

Homework Statement A rugby ball of mass 400 grams is to be kicked from ground level to clear a crossbar 3m high. The goal line is 12m from the ball, and the junior rugby player can impart a maximum speed of 4√g ms−1 to the ball. (a) Modelling the ball as a projectile moving under...

Homework Statement A model car of mass m moves on a horizontal track so that its displacement r from a fixed origin at time t is given by r(t)=2cos(t)i + sin(2t)/sqrt2j where 0<t<2pi (a) If r is the position vector of a particle, explain the physical significance of r . r and show...

Hi Tim! I see where this comes from, I made a mistake elsewhere and carried it forwards. You are quite correct, as always! I get the constant to be -3.65. Giving a max height of the ball to be 383.55 metres. Which just doesn't seem right for something thrown at 20m/s

Hi Tim :) I rearranged the equation to get C, so I can solve the solution to find x. By doing this I got xg/(b2/2)ln(b2+v2) When I put in x's initial value of zero, I get 0/... which is infinity.

I don't understand what you mean. If x=0 then the top half of the equation is zero. So the only solution that could work is if the bottom half equals zero. But this is not correct, because if I put C=0 into the next part of the question where we find its max height, I get a crazy answer. This...

Hi Tim, I got the equation to the following. x = -((b2/2)ln(b2+v2)+C)/g The initial values, are b2 = 1090 (b=root(mg/0.2D2)), v = 20, g = 9.81 When I re-arrange for C I get C = xg/((b2/2)ln(b2+v2)) = 0.0036m The two things that stick out here, 1) the initial value when taking...