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Speed of a falling magnet in copper pipe

Hi everyone!

I don't understand how one would measure the final velocity of the magnet?
I thought maybe v=2s/t (suvat formulae, s=distance, t=time) but acceleration is not equal to a constant g is it?
Please help!
Screenshot (130).png
Thanks!
(edited 5 years ago)
Original post by Geometrica
Hi everyone!

I don't understand how one would measure the final velocity of the magnet?
I thought maybe v=2s/t (suvat formulae, s=distance, t=time) but acceleration is not equal to a constant g is it?
Please help!
Screenshot (130).png
Thanks!


You would know why the acceleration is NOT constant when you learn electromagnetic induction.

You can measure the speed of the magnet using light gate sensors. See the following video.
https://www.youtube.com/watch?v=peh8cpHmOm4

You can also use tick tape timer.


I would leave the detail of the experimental setup to you.
Reply 2
Original post by Eimmanuel
You would know why the acceleration is NOT constant when you learn electromagnetic induction.

You can measure the speed of the magnet using light gate sensors. See the following video.
https://www.youtube.com/watch?v=peh8cpHmOm4

You can also use tick tape timer.


I would leave the detail of the experimental setup to you.

Thank you for your reply and the link. :smile:
Yes I understand there will be a force on the magnet due to induction which reduces its acceleration. So would I place only one light gate at the bottom of the pipe, measure the length of the magnet and then use the time recorded between the front and back ends of the magnet? I don't know...?
(edited 5 years ago)
Original post by Geometrica
So would I place only one light gate at the bottom of the pipe, measure the length of the magnet and then use the time recorded between the front and back ends of the magnet? ....?


Not sure what are you asking here.
Reply 4
Original post by Eimmanuel
Not sure what are you asking here.

Is my 2nd method valid to determine final velocity (correct physics)? Sorry my brain is not working anymore:smile:
(edited 5 years ago)
Original post by Geometrica
Is my method valid to determine final velocity (correct physics)? Sorry my brain is not working anymore:smile:


Original post by Geometrica
Thank you for your reply and the link. :smile:
Yes I understand there will be a force on the magnet due to induction which reduces its acceleration. So would I place only one light gate at the bottom of the pipe, measure the length of the magnet and then use the time recorded between the front and back ends of the magnet? I don't know...?



What do you mean by front and back ends of the magnet?

How does the placing of one light at the bottom the pipe allow you to measure the speed of the magnet leaving the pipe?
Reply 6
Original post by Eimmanuel
What do you mean by front and back ends of the magnet?

How does the placing of one light at the bottom the pipe allow you to measure the speed of the magnet leaving the pipe?




Because the light gate will record the time during which the beam is broken right?
Reply 7
Original post by Eimmanuel
What do you mean by front and back ends of the magnet?


I mean just like the ends of the magnet, because it is a rectangle.
Original post by Geometrica
Because the light gate will record the time during which the beam is broken right?


Are you asking a question or making a statement?
Reply 9
Idk, I'm just not 100% sure if that is a valid method.
Original post by Geometrica
Idk, I'm just not 100% sure if that is a valid method.


Original post by Geometrica
Because the light gate will record the time during which the beam is broken right?


Indeed, the light gate will record the duration of the time that the magnet falls through the light gate. And you can have the length of the magnet divided by the duration of the time to find the average speed of the magnet leaving the pipe.
The tricky part is how are you going to quantify the average speed is the speed of the magnet leaving the pipe the pipe.

In certain examination board, students don’t need to quantify it but in certain examination board, students need to quantify it.
Original post by Eimmanuel
Indeed, the light gate will record the duration of the time that the magnet falls through the light gate. And you can have the length of the magnet divided by the duration of the time to find the average speed of the magnet leaving the pipe.
The tricky part is how are you going to quantify the average speed is the speed of the magnet leaving the pipe the pipe.

In certain examination board, students don’t need to quantify it but in certain examination board, students need to quantify it.

Thanks for the help. I'm doing CIE, and I think it should be okay.

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