Recent content by mcairtime

Hello, I am wondering why such a large voltage can be generated when the switch in a circuit containing an inductor is opened. The following is from a set of Electromagnetism course notes: "The 1.5 V supply in the circuit below is insufficient to light the neon lamp. A neon lamp needs about 80...

Hello, I have worked out where my issue was with the help of haruspex. As well as the equation s = ut + 0.5at^2 there is another equation s = vt - 0.5at^2 (where u is initial velocity and v is the final velocity). I was getting different answers when I used these two different equations and...

Yes, that is all crystal clear now. I was having a complete mental block. Seems obvious now. Thanks very much indeed.

Hi Doc Al, Thanks for your response. I'm afraid I am not quite following. As far as I'm aware I'm maintaining down as the positive direction throughout the entire question. In part a) we have s = +80 m u = +4 m/s v = ? a = +9.8 m/s^2 t = ? We use this to find that v = + 12sqrt(11) m/s For...

Yes, assuming we take g to be 9.8, the girls mass will be 30kg. In fact the equation is really 0.5mu^2 + mgh = 413 + 0.5mv^2 where v is her final speed at the bottom of the slide. The left hand side of the equation is the total energy that she starts with at the top of the slide, the right hand...

I think the solution is as follows: She starts off with potential energy mgh (where mg is the girl's weight (294 N) and the h = 2.22 m) and with kinetic energy 0.5mu^2 (where u = 0.46 m/s is her initial speed). All these values we can calculate explicitly. By the time she reaches the bottom...

Hi there, Sorry in advance. This problem is very simple but I can't see where I'm going wrong or what I'm missing. It may even be a numerical mistake, although I have run the numbers a few times. I have a feeling that I'm going to kick myself but anyway... A ball is projected vertically...

Hello, My GCSE class just did a practical investigation into how the width of a Bunsen's air hole affects the temperature change of a beaker of water. The entire class found as expected that the size of the temperature change increased as the hole was opened further, but they all found that...

Hello, I am thinking of applying for the above course and just trying to gauge how difficult it is really. I have a 2:1 in physics from Cambridge, and although at times I felt like I was knocking my head against a brick wall overall I think I might have pulled to a first if the exams had...