You are Here: Home >< Maths

# Centre of mass question watch

1. 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

.
2. (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

.
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...
3. (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

.
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?
4. In hindsight, my reply times are unhealthy...
5. am I too late yet again?
6. sorry, I posted the wrong picture haha. Here is the question I was referring to.

https://goo.gl/photos/xqmXY6kddjcYoJ5j8
7. (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.
8. (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:
Show
9. (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:
Show
Thanks, that should help as I saw a solution with something similar.

### Related university courses

TSR Support Team

We have a brilliant team of more than 60 Support Team members looking after discussions on The Student Room, helping to make it a fun, safe and useful place to hang out.

This forum is supported by:
Updated: February 28, 2016
Today on TSR

### Top unis in Clearing

Tons of places at all these high-ranking unis

Poll
Useful resources

### Maths Forum posting guidelines

Not sure where to post? Read the updated guidelines here

### How to use LaTex

Writing equations the easy way

### Study habits of A* students

Top tips from students who have already aced their exams