How fast is this bead traveling down the wire

• Ronaldo21
In summary, the big metal bead sliding down an upright friction-free wire has the maximum speed at point B, as it has the least potential energy at that point. The relationship between points B, D, and E is that they are all at the same height. To calculate the numerical speed at these points, a reference level must be chosen along the horizontal line passing through these points. However, the speed at point C cannot be calculated without knowing the distance between point B and point C.
Ronaldo21
A big metal bead slides due to gravity along an upright frictiion-free wire. It starts from rest at the top of the wire as shown in the sketch. How fast is it traveling as it passes.

http://https://www.physicsforums.com/attachment.php?attachmentid=22509&stc=1&d=1260854052

Point B?
Point D?
Point E?
At what point does it have the maximum speed?
I got B for this because it goes down really fast.

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The way to do this question is to use conservation of energy.

Gravitational PE at top goes into PE + KE as the bead slides down.

so what do we exactly do?
because we don't have the number to d and e. i think i get b.

Ronaldo21 said:
so what do we exactly do?
because we don't have the number to d and e. i think i get b.

I think you might want to review the concept of conservation of energy for objects falling in a gravitational field. Briefly, you pick a reference level where potential energy = 0. When the object is above that level its PE is given by mgx where x is its current height. The conservation of energy equation goes as

Energy at the start = $mgx + \frac{1}{2} m v^2$

Here your energy at the start is mgh. Now look at your drawing carefully. Where IS the object going the fastest? This is subtle because it's where the PE is the LEAST. What is the relationship between points b, d, e? Which one is highest? Or they all at the same height?

hmm i think i get it so the answer will be some kind of formula then right??

Ronaldo21 said:
hmm i think i get it so the answer will be some kind of formula then right??

Actually you can get a numerical answer for the speed at points b, d, e if you pick your reference level (PE = 0, x = 0) along the horizontal line passing through b, d, e. You cannot get a numerical answer for point c because you don't know how far below point b it is.

1. How is the speed of the bead calculated?

The speed of the bead can be calculated by dividing the distance the bead travels by the time it takes to travel that distance.

2. What factors affect the speed of the bead?

The speed of the bead can be affected by the angle of the wire, the length of the wire, the mass of the bead, and the force applied to the bead.

3. Is the speed of the bead constant?

No, the speed of the bead can vary depending on the factors mentioned above. Additionally, friction and air resistance can also affect the speed of the bead.

4. How is the speed of the bead measured?

The speed of the bead can be measured using a stopwatch or a motion sensor. The distance the bead travels can be measured using a ruler or measuring tape.

5. Can the speed of the bead be faster than the speed of light?

No, according to Albert Einstein's theory of relativity, the speed of light is the maximum speed at which anything can travel in the universe. Therefore, the speed of the bead cannot exceed the speed of light.

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