Recent content by sean39

Ok. Thank you. What is the formula to determine the rate of acceleration? Does this mean with zero weight attached to the.blade it will asymptotically approach 100 rpm? What about with a 2 kg weight?

This is just a question that has been bothering me. I am not a student of physics, which is probably clear from my question. Hope it at least makes sense: You have a windmill with no friction. The wind is blowing at a constant speed causing the windmill to spin at 100 RPM.(a) The windmill...

I appreciate all the replies. Let me see if I am interpreting these answers correctly. I think most of you are saying that if the universe had started from a singularity, then it would be true that no two points could be further apart than the distance light could have traveled. But this is...

In Brian Greene's book, Fabric of the Cosmos, he mentions that not enough time has passed for light from some parts of the universe to reach us. (I'm paraphrasing, but I think this is pretty much what he said, and I've heard similar statements from others). How is this possible if the universe...

Ok. Thanks. This is really, really helpful. I think I have a much better understanding now. So from a theoretical standpoint, isn't a motor just something that takes some form of energy and converts it into mechanical energy (i.e., motion)? Would all motors have a parabola-shaped function...

Ok. Now I think we're getting somewhere. If f(x) is strictly increasing and g(x) is strictly increasing, then f(x) * g(x) will be strictly increasing. So for f(x) * g(x) to have a maximum, these functions are either going in different directions (i.e., one is increasing and the other is...

Thank you, but can you please elaborate to explain what I am misunderstanding? It seems to me that we are trying to perform two steps: (1) convert kinetic energy of the air into the kinetic energy of the drivetrain, and (2) convert the kinetic energy of the drivetrain into some other form of...

Ok, but it's still something. And less motion = less friction, so shouldn't a machine that exerts force over a shorter distance against higher resistance be more efficient than a machine that exerts the same amount of force over a larger distance? The force required to push a bowling ball up a...

Thanks, it's been a very long time since I took physics, so I apologize that I am having trouble with these concepts. From your answers, I can't tell whether I have made my question clear, or if I am just not recognizing the answer in your response. I think I get the equation above. So...

Ok. I kind of understand, but not quite. I'm going to switch between another analogy. Hope that doesn't confuse the question too much. Here's the analogy: Say you use a certain amount of force to pushing a weight up a slight incline. Compare this with using the same amount of force to push...

Someone please help me understand this concept that has always confused me: Is the movement of the turbine itself a loss of efficiency since that is energy that is not being converted into other (e.g., electrical) energy? For example, if a wind turbine is not hooked up to anything, it will...