You are Here: Home >< Maths

# M2 moments equilibrium toppling question watch

1. Attachment 532753532755

Im not sure how to even attempt this
(Part 2)
Attached Images

2. (Original post by tavtavtav)

Attachment 532753532755

Im not sure how to even attempt this
(Part 2)
I would take moments about the point of the base touching the ground using the centre of mass you found in the previous part and the weights. If the resultant movement is anticlockwise then the toy will move so the rod is upwards
3. (Original post by TheBride)
I would take moments about the point of the base touching the ground using the centre of mass you found in the previous part and the weights. If the resultant movement is anticlockwise then the toy will move so the rod is upwards
But without knowing the reactions and only the centre of mass I won't be able to get a resultant moments.
4. (Original post by tavtavtav)
But without knowing the reactions and only the centre of mass I won't be able to get a resultant moments.
Was the COM for the whole toy or just the base? I can't see from the pics
5. wrong post. sorry/
6. Consider this: The toy can only topple in two ways, around the black ball part or the semicircle part. If it was going to topple around the black ball/dot part the COM would need to be super far to the right, this is obviously ridiculous. Thus the only real way its going to topple is around the semi circle, and this only is going to happen if the COM is further left of the contact point between the semi circle and ground. You can use the known lengths to get the angle, and trig to work out the horizontal distances, and compare to see if the COM is left of the critical point or not.
7. (Original post by TheBride)
Was the COM for the whole toy or just the base? I can't see from the pics
Whole toy
8. (Original post by tavtavtav)
Whole toy
Then I agree with the post above; I think it's just a case of working out the trig and seeing if the COM is to the left or not

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: May 16, 2016
Today on TSR

### Tuition fees under review

Would you pay less for a humanities degree?

### Can I get A*s if I start studying now?

Discussions on TSR

• Latest
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

## Groups associated with this forum:

View associated groups
Discussions on TSR

• Latest

The Student Room, Get Revising and Marked by Teachers are trading names of The Student Room Group Ltd.

Register Number: 04666380 (England and Wales), VAT No. 806 8067 22 Registered Office: International House, Queens Road, Brighton, BN1 3XE