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Riddles with a Prize, by Mantus Anchors

13K views 93 replies 32 participants last post by  ebs001 
#1 ·
Ok here are the rules: I will post the riddle and the first person to answer the riddle correctly gets to win a Stainless Steel Mantus Hook with free shipping.
We will try it this week and see how it goes,,,

Ok so here is the riddle:

There are three switches downstairs. Each corresponds to one of the three light bulbs in the attic. You can turn the switches on and off and leave them in any position.
How would you identify which switch corresponds to which light bulb, if you are only allowed one trip upstairs?

Post the answer on this thread first and win a Mantus Chain Hook!
 

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#74 ·
If the weight of the spring is negligible, yet by pushing the head down the spring causes the head to pop up, the weight of the head has to be negligible. Both now have to be nearly the same weight if the head was pushed down to completely compress the spring. And there's the big unknown. How far does the spring have to be compressed to cause the head to pop up? Of course you have to define the word "pop" when using it here. Does that mean pop up like a jack in the box, or does it merely mean making the head rise back up, regardless how quickly?

For the box to be lifted, enough force has to be created through the compression of the spring to cause both the head and the box to be lifted off the surface the box is sitting on. The force of the spring pushes the head upward at a velocity sufficient enough to stretch the spring beyond it's natural state and in doing so create sufficient stretch in the spring that the box will be lifted off the surface before the velocity of the head stops and begins to succumb to gravity and the forces of the spring returning to its natural state.

Since the spring's weight in negligible, the weight of the box and the head would have to be negligible, barring any super-spring, space-age steel that the spring might be composed of.

The weight of all three would have to be negligible relative to the weight of any two, in other words, all are almost zero. Unless you state the head compressed the spring half way to cause it to pop up like a jack in the box, which would allow you to surmise that fully compressing the spring could cause the spring to decompress at such a rate as to lift the box off the surface as described above.

This is an answer that could be theorized in a calculus equation but I forgot most of the calculus symbols. It's been a while.
 
#77 · (Edited)
F = mass * acceleration (F= m*a), and weight = mass * gravity

In order for the box to "jump" off the surface it's sitting on (assuming earth with g=9.8m/s^2), the upward force, F(u), would need to be greater than the weight of the box which is (M+m)*9.8 m/s^2.

Whatever downward force, F(d), is applied to the Jack will be returned with the Jack is released. Therefore, the force applied to just overcome the weight of the Box+Jack would be F(d) > (M+m)*9.8 m/s^2

If this isn't the answer, then all I can say is F(u). ;-)
 
#85 ·
Force has to be...

Which radically assumes the spring can in fact absorb and return that force. In practice, the spring may be too weak to store that much energy, resulting in a total failure to launch the box.

Rather than assuming the physical properties of a spring, I maintain the box is located at a LaGrange point and it will plummet to a death in a gravity well before the box ever leaps up after Jack. A much simpler assumption.
 
#88 ·
If you have to ask, Grasshopper, then you are not yet ready.....
Perhaps, but I do know the definition of a riddle:

rid·dle/ˈridl/ Noun: A question intentionally phrased to require ingenuity in ascertaining its answer.

No ingenuity required for the jack in the box, just the ability to translate mass and gravity into a mathematical equation. That's a problem set. The light switch question was a riddle.
 
#90 ·
No ingenuity required for the jack in the box, just the ability to translate mass and gravity into a mathematical equation. That's a problem set. The light switch question was a riddle.
A man is standing before a portrait painting on the wall, points to the portrait and says to the person standing next to him, "Though brothers I have none, that man's father is my father's son."

Who is the person in the portrait?
 
#91 · (Edited)
Is that one as old as the Sphinx?

Spoiler alert:

It is used as a test of cognitive skills because if you can rearrange the relationships to a logical order, it becomes father-son-(who is also a father therefore his son is) grandson (son of speaker).

Now for a true mystery, how is it that a random length of twine or rope can tie itself in knots, but if you held the same piece in your hands all day and flipped it around, you couldn't get it to tie itself up in knots at all?
 
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