Exploring Work (W) and its Speed Limits

In summary, the conversation discusses the concept of infinite speed in physics, specifically in relation to work and rotational motion. It is explained that the maximum speed of an impulse in a material is determined by the speed of sound in that material, which is usually very high in solids. This concept also comes up in relativity, where students may initially think they can break the speed of light limit with a long stick. However, it is clarified that this is not possible and the conversation ends with a humorous comment about reading minds.
  • #1
Hypercubes
38
0
Hello,

I'm sorry if this question seems a bit ignorant, but I don't yet have an extensive knowledge of physics. My question is, does work (W) have infinite speed? For example, if one had a rod, and one turned it, would the rotational motion be transferred from the end of the rod where one was turning, to the other end instantly? Or would kinetic energy be transferred through vibrations? In the latter case, what would be the maximum speed possible?

Thanks in advance.
 
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  • #2
The maximum speed of an impulse in a material is (basically) the speed of sound in that material. You don't notice because the speed of sound in most solids is very high, eg in high strength steel it's about 6000m/s, compared to 350m/s in air
 
  • #3
Ah, that makes sense. Thanks.
 
  • #4
It comes up often in relativity. The fist thing a student thinks of is, if i have a light year long stick I can prod somebody a lightyear away and break the speed of light limit.
 
  • #5
NobodySpecial said:
It comes up often in relativity. The fist thing a student thinks of is, if i have a light year long stick I can prod somebody a lightyear away and break the speed of light limit.

! It's like you read my MIND !

Actually, when I first learned relativity I tried to imagine a galaxy long stick spinning about an axis perpendicular to its length. Specifically I tried to figure out what it might look like if a point at L/2 were going 0.99c, how fast is the tip moving?!
 

1. What is work and how is it defined?

Work, in scientific terms, is defined as the transfer of energy from one object to another. It can be calculated by multiplying the force applied to an object, by the distance the object moves in the direction of the force.

2. What are the units of work and how are they measured?

The units of work are Joules (J). Work is measured by calculating the product of force (N) and displacement (m).

3. What are the speed limits of work and why are they important?

The speed limit of work is the maximum amount of work that can be done in a given amount of time. This limit is important because it determines the efficiency of a system and can help optimize processes.

4. How does friction affect work?

Friction is a force that opposes motion, thus it can reduce the speed at which work is done. This means that more force is required to overcome friction and do the same amount of work, resulting in a decrease in efficiency.

5. What are some examples of work being done at its speed limit?

Examples of work being done at its speed limit include a car traveling at its maximum speed, an athlete performing at their peak performance, or a machine operating at its maximum capacity. In these cases, any increase in speed would require an increase in force or energy, making it difficult to exceed the speed limit of work.

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