Special Relativity and length contraction

In summary, the conversation discusses the concept of length contraction, which is the phenomenon where an object appears shorter when it is in motion relative to an observer. The conversation specifically mentions a meter stick moving at high speed parallel to its long axis, and the question asks at what speed the meter stick is moving relative to the observer if it measures to be 1.00 ft. The conversation also clarifies the definition of "proper length" and provides a hint for solving the problem.
  • #1
ledhead86
59
0
A meter stick moves past you at great speed. Its motion relative to you is parallel to its long axis.

If you measure the length of the moving meter stick to be 1.00 ft (1ft=.3048 m), for example by comparing it to a one-foot ruler that is at rest relative to you, at what speed is the meter stick moving relative to you?


The only thing I can figure out is that one foot is the proper length. I'm completely confused about the rest.
 
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  • #2
OK, here's a hint: This is a problem in length contraction.

What do you know about length contraction?
 
  • #3
ledhead86 said:
The only thing I can figure out is that one foot is the proper length.


No, the proper length is the length that would be measured by someone who is moving along with the meter stick (like a witch riding a broomstick :devil: ). So the proper length of a meter stick is one meter.
 

Related to Special Relativity and length contraction

1. What is Special Relativity?

Special Relativity is a theory proposed by Albert Einstein in 1905, which explains the relationship between space and time. It states that the laws of physics are the same for all observers in uniform motion, regardless of their relative velocity.

2. What is length contraction in Special Relativity?

Length contraction is a phenomenon that occurs in Special Relativity, where the length of an object appears to decrease when it is moving at a high velocity. This is due to the distortion of space and time caused by the object's motion.

3. How does length contraction affect measurements?

Length contraction affects measurements by causing objects to appear shorter when they are in motion. This can be observed in experiments such as the famous "pole and barn paradox" where a pole moving at high speed appears shorter to an observer than it actually is.

4. Does length contraction only occur for objects moving at close to the speed of light?

Yes, length contraction only becomes significant for objects moving at speeds close to the speed of light. At everyday speeds, the effects of length contraction are negligible and cannot be observed.

5. What are some real-life examples of length contraction?

One example of length contraction is the effect of cosmic rays on Earth's atmosphere. These high-speed particles appear to be shorter than they actually are due to their incredibly high velocities. Another example is the contraction of atoms in a particle accelerator, which allows them to reach higher speeds without breaking apart.

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