Recent content by Racer_Rob

I've tried doing a force balance for block A first of all. I've written it out in terms of forces normal and parallel to the contact surface (rather than breaking these down into X and Y components. http://i.imgur.com/TL0g7fr.jpg If you think this looks somewhat correct I'll go on and do a...

Hm, will there additionally be a Fcosθcosθ term to add to that? I've got this from the X direction reaction force at the interface between A and B.

So that's going to be a normal force on the left side of A equal to the sum of all the resolved forces that are acting in the -X direction i.e. μ1Fcosθ sinθ, and I'll need to include this in the force balance?

In the system that this is from, component A is constrained such that it's only able to move in the Y axis.

Homework Statement Component A is pushed vertically down with a known force F into component B. The angled surface of B is parallel to the angled surface of A. The contact between A and B is rough and so is the contact between B and the ground. The coefficients of friction are known and so is...

Hi Chet, those assumptions are correct, I was imagining 1D conduction. Although surely once the temperature gradient through the large object is a straight line then it's steady state not transient because the temperatures are not changing with time from then on. I think I over complicated the...

Say you have a flat resistor that is producing heat. You place the resistor against a sheet of steel and wait for equilibrium. One side of the steel is now at the same temperature as the resistor (assuming negligible contact resistance), the other free-air side of the steel is at a lower...

I'm not sure if it's a VCSEL based laser I'm afraid, all I know is it's a diode-pumped Nd:YAG laser which is really designed for Particle Image Velocimetry (PIV). Unfortunately I don't have a micrometer stage but the power meter I have does at least show the expected power. My plan at...

The lenses were brand new for the experiment so I'm as confident as I can be that they are correct. The convex lens is BK7 and the concave is UV grade fused silica because this could be supplied uncoated and was needed to deal with the high fluences. I suspect a poorly collimated laser is the...

Thank you both for your detailed responses. I didn't manage to get back on the laser today but I will tomorrow so I can update you on the experimental side of things then. I've checked and double checked this, they're definitely the correct way around. I also checked the surfaces of the...

That's correct but I actually saw a much larger (around 2cm diameter) and out of focus spot. I tried varying the lens separations and the distance between the convex lens and the laser source but saw no improvement.

I'm trying to focus a 3mm diameter laser beam (527nm) to a 0.3mm spot size. According to this online calculator I need a +500mm focal length lens and a -50mm FL lens separated by 450mm. However, in practice this did not produce a focused spot. I'm assuming this calculator has made some...