Recent content by Ellio

So tell me if I'm wrong, the left spectrum (white) and the right one (red) show spectra of two different galaxies (with different distances), right ? Why is it possible to know the velocity of the red-shifted spectrum by comparing it to the left one ??

Hello, I hope you are very well ! I have a physics practical test where I have to find the gravitational acceleration with the Atwood machine: I've found 9.27 m/s² and have to say what could have caused this slight gap. They say that there is no friction in this experiment. I can't really...

Hello, I hope you are all having a great day ! I've got a physics test in a couple of days and I have some questions:1. In a calculation, if the acceleration is in m/s², I presume the speed also has to be in m/s and not in km/h ? 2. So with this graph (v with t), I have to find the total...

Ok thank you very much for your answers !

Hello, I hope you are all very well ! Let's say a man, standing on point "0 m" throws a ball 10 m in the air. The gravitational force goes in the opposite (down (always)) of the action (up): I supposed it's -9.81 m/s². The same action but this time the man stands on the point "10 m" and the...

Ok thank you very much ! (Yes it's the setup we used.)

This was the instrument. The band was held where there's the red circle. The yellow arrow shows the vibrator which hit the band 50 times/s. (The tape was of course vertical in the experiment.)

I think the two factors causing this deviation are the vibrator (hitting the tape 50 times/s) and the measurement of the distance between each mark with a ruler (±1mm of error) But isn't there any other that I could have forgotten ?

Well, thank you all for your answers. But I wasn't really claiming thay my measurement were 'wrong'. 4% of deviation is indeed nothing, I'm of course leaving my answer. I just wanted to know by curiosity what are the factors that could cause this very slight deviation (atmosphere, ...).

The air surrounding the room, I presume.

Hello I hope you are all very well ! So I have a practical work in physics. The experiment was to release a long tape with a mass of 40g at the end from a certain height. An instrument would hit the tape 50 times/s and put a mark each time. From that we had to do a graph x(t²) and a series of...

Understood, thank you so much for your help I appreciate it !

Oh ok so it isn't always 10% of one unit ? Could I in this case choose myself the percentage ?

Ok but how do I determine the error percentage ?

There is no error bars yet. That's actually the topic of my question. I would like to know how to do error bars on a graphic (in percentage for example).