Year 12s: what will be the first way you research your future options? >>

Centre of mass question

Hi,

Please may I have some help with this centre of mass question, question number 3 in the picture. I am specifically stuck on part a. Thank you :smile:

Reply 1

Zacken

Original post by albyedw

Hi,

Please may I have some help with this centre of mass question, question number 3 in the picture. I am specifically stuck on part a. Thank you :smile:

Can you split the lamina into two different shapes that you can easily find the centre of mass for? Then find the mass ratios of each different shape and compute the centre of mass, etc...

Reply 2

KaylaB

Original post by albyedw

Hi,

Please may I have some help with this centre of mass question, question number 3 in the picture. I am specifically stuck on part a. Thank you :smile:

So if you have completed question 2, I assume you can find the centre of mass of a rectangle?
What you can do for questions similar to question 3 is split it up. So this can be split up in to two separate rectangles. Could you find the centre of mass for the two separate rectangles?

Reply 3

Zacken

In hindsight, my reply times are unhealthy...

Reply 4

TeeEm

am I too late yet again?

Reply 5

albyedw

sorry, I posted the wrong picture haha. Here is the question I was referring to.

https://goo.gl/photos/xqmXY6kddjcYoJ5j8

Reply 6

Ayman!

Original post by albyedw

sorry, I posted the wrong picture haha. Here is the question I was referring to.

https://goo.gl/photos/xqmXY6kddjcYoJ5j8

The entire thing is a wire framework which can be split into individual rods. I suggest splitting it into 4 or 5 rods, finding each individual rod's COM and then finding the shape's COM. I'll form a table to get you started in a few.

Reply 7

Ayman!

Original post by albyedw

...

Try making a table with the masses and centres of mass from AB and AE of each wire component like the one I've attached. After that, it should be pretty simple by taking moments about the axis AE!

Spoiler

Reply 8

albyedw

Original post by aymanzayedmannan

Try making a table with the masses and centres of mass from AB and AE of each wire component like the one I've attached. After that, it should be pretty simple by taking moments about the axis AE!

Spoiler

Thanks, that should help as I saw a solution with something similar.