# Recent content by iffydroplight

1. ### Constant acceleration problem

Up an down times are equal so begin by solving for descent data. At 76.1cm, vertical velocity is zero. Solve your second equation for s. Becomes your time equation. Calculate velocity after falling 14.4cm. This can be plugged into vi in the time equation to determine seconds falling...
2. ### Free-Body diagram of block on plane; both move

Friction is what makes the block track with the incline plane at its upper part . Normally, the force vector applied would be purely gravity-enforced. Friction would be applied straight upward. In the case of your moving incline plane, the vector is no longer applied straight up but is...
3. ### Simple Suspended Weight Force

I believe you have it correct. The measurement point is insensitive to the location of the mass. Otherwise, you would need to consider such nonsense as the top half of each 1.0 N box versus its bottom half. Consider that your string is connected to the top of the heavy chain, light chain or...
4. ### Is a refrigeration laser thermodynamically possible?

Never forget that Overall head transfer = Overall heat transfer coefficient * Area * (Temperature of hot surface - Temperature of cool surface). That is, Qdot=UA(deltaT). So, with the sun radiating into space's 4 Kelvin heat sink it is working at max heat transfer rate for the surface area...
5. ### Is a refrigeration laser thermodynamically possible?

Having written the preceding, there are two lasers at work in the scenario. The first is the refrigeration laser that cools the inward-facing shell. The second is the communication laser transmitting to space. Okay, so what is going on here is that we have outward thrust supplied by the...
6. ### Is a refrigeration laser thermodynamically possible?

Taking the argument to extreme, we are talking about covering an area of the sun and dumping the heat flux across that area to a heat sink of nearly absolute zero temperature. That is what the sun is already doing and it retains its high 'surface' temperature anyway. If we take the...