There are some puzzling problems there. I'm curious if anyone knows what the answer to #3 is? (You can either post it hidden as a spoiler or PM me.) I don't see how such a heavy sandbag could possibly be blown that distance with just a drinking straw.I found this link with a collection of very interesting physics problems from Duke University's physics department. Maybe some of the people in this forum will find it useful either as educational reference, or simply entertainment.
To solve that problem, consider this word as a hint: resonanceThere are some puzzling problems there. I'm curious if anyone knows what the answer to #3 is? (You can either post it hidden as a spoiler or PM me.) I don't see how such a heavy sandbag could possibly be blown that distance with just a drinking straw.
Ah, that gave it away. I don't think I would have ever thought of that. I guess I have a lot to learn.I would simply blow pulses on the sand bag in resonance with its swing (a constant) until it knocks the bottle over. Might take awhile.
John
You could've used a resistor symbol to represent the light bulb!Here's my answer to #34. Couldn't find a symbol for an incandescent bulb, but the principle is the same. The diode across the bulb shorts it, so it doesn't light with that part of the cycle.
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Damn Eagle took forever to draw.
John
Bottom line... I'm glad you have all that free time in your hands... ha ha ha...I had a hard enough time finding the SPST switches, and I use Eagle all the time. I did think about a resistor, but then I would have wanted to make a new device with little arrows to indicate the light. We make our own misery. Bottom line, I am not real fast at the computer.
John
I hadn't thought of that... down here's 16°C (61°F) and by Thursday it's going to be a rather nice 22°C (72°F)My involvement in electronics is proportional to how cold it is.
Neither have I... the question is: what's the volume of three equal cylinders that intersect orthogonally?I find Challenge #18 "Volume of a Holey Cube" intriguing... I haven't found a solution yet.
As a start, I would reduce it so a simpler problem. Imagine an inner cube that is the same size on each side as the diameter of the holes and this is centered in the main cube. Now imagine that the holes are only bored down to the face of the inner cube. The amount of material removed at this point is trivial to determine.I find Challenge #18 "Volume of a Holey Cube" intriguing.
Consider a solid silver cube whose side has length L=4 cm. If three holes of diameter D=3 cm are drilled completely through, and perpendicular to, the centers of all the faces of the cube, what is the volume V of the remaining metal in the cube?
I haven't found a solution yet.
So you are claiming that if I take a cube in turn it on a lathe along three orthogonal axes that the result will be a sphere?It seems simple to me.
That's why I subtracted 1 sphere from each cylinder.
And then only added 1 back in. Because there is only one.
I read some of the links' examples.....I believe a lot were trick questions.