At what velocity should relativity be taken into account

AI Thread Summary
Relativity should be considered when velocities approach a significant fraction of the speed of light (c), which is approximately 300,000,000 m/s. The discussed velocity of 6.5 x 10^6 m/s is about 2% of c, resulting in a minimal error of around 0.03% if relativistic effects are ignored. For most practical calculations, especially with limited precision, this velocity can be treated as non-relativistic. However, if higher precision is required or if velocities increase significantly, incorporating relativity becomes essential. Understanding the context and precision needed for calculations is crucial when determining the relevance of relativity.
moonkey
Messages
22
Reaction score
0

Homework Statement


I have exams coming up and I'm just looking for an idea of when relativity should be taken into account. For example I'm just going over a question involving photoelectric effect and potential fields and de Broglie and all that jazz and the final velocity of the electron turns out to be around 6.5x106ms-1. Should I take relativity into account for this velocity or is it still safely within the margins of non-relativistic velocity? I'm thinking that it is safe to assume that it is non-relativistic but I would like some advice just in case such a question arises that involves a greater velocity.


Homework Equations





The Attempt at a Solution

I have exams coming up and I'm just looking for an idea of
 
Physics news on Phys.org
OOPS. Forget I said anything (it turned out to be not relevant, so I deleted my comment)
 
At a first glance, I'd say it depends on the precision that you want.
Since c is 300.000.000 m/s your speed is a 2% of c, which gives you an error of 0.03% if you ignore c (if I am not wrong).

If you use just only 3 figures (e.g. 0.134) in your data, then ignore it.
 
That makes perfectly good sense.

Thanks Quinzio
 
Thread 'Collision of a bullet on a rod-string system: query'

Thread 'Collision of a bullet on a rod-string system: query'

In this question, I have a question. I am NOT trying to solve it, but it is just a conceptual question. Consider the point on the rod, which connects the string and the rod. My question: just before and after the collision, is ANGULAR momentum CONSERVED about this point? Lets call the point which connects the string and rod as P. Why am I asking this? : it is clear from the scenario that the point of concern, which connects the string and the rod, moves in a circular path due to the string...
View full post »
Thread 'A cylinder connected to a hanged mass'

Thread 'A cylinder connected to a hanged mass'

Let's declare that for the cylinder, mass = M = 10 kg Radius = R = 4 m For the wall and the floor, Friction coeff = ##\mu## = 0.5 For the hanging mass, mass = m = 11 kg First, we divide the force according to their respective plane (x and y thing, correct me if I'm wrong) and according to which, cylinder or the hanging mass, they're working on. Force on the hanging mass $$mg - T = ma$$ Force(Cylinder) on y $$N_f + f_w - Mg = 0$$ Force(Cylinder) on x $$T + f_f - N_w = Ma$$ There's also...
View full post »

Similar threads

Calculate the relative angular velocity
Replies
2
Views
2K
Body attached to a block by a spring, shaped like an inclined plane
Replies
1
Views
884
At what velocity should relativity be taken into account
Replies
1
Views
2K
Insights Addition of Velocities (Velocity Composition) in Special Relativity
Replies
3
Views
6K
Solving for velocity in relativistic momentum
Replies
2
Views
2K
Why Are Relative Velocities in Elastic Collisions Frame-Independent?
Replies
4
Views
1K
Relative Velocity of Object C to Object A = 10 m/s
Replies
9
Views
2K
Relativity: Cosmic ray proton traveling to Earth
Replies
12
Views
933
Relativity - velocity of object travelling perpendicular to the observer
Replies
4
Views
2K
What Is the Velocity of the Krypton Atom Relative to the Tube?
Replies
11
Views
4K

Hot Threads

Recent Insights

Back
Top