Mechanics - centre of mass

Hello everyone,

I don't know how to do ai - I thought that it would be 35 cm from AE, but the answer is 28.4 cm...

Why is this - how does the rod affect where the centre of mass is?

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Reply 1

ghostwalker

Original post by Electrogeek

...

You seem to have just assumed it's half-way across the letter, but not taken into account the extra mass on the left.

Work it through as normal, and see what you get. Post working if it's not coming out.

Reply 2

Xphoenix

Original post by Electrogeek

Hello everyone,

I don't know how to do ai - I thought that it would be 35 cm from AE, but the answer is 28.4 cm...

Why is this - how does the rod affect where the centre of mass is?

Yeah like the other guy said you assumed...

One tip is since it's a rod, you need to take the weight component of each part into consideration (big mistake to make).

EDIT: Also post your workings so we can see what you're dong and give better advice

Just work it out as normal after that forming equations.

Reply 3

Electrogeek

I know that the calculation I have to do is:

( (Mass of ABCD) (centre of mass of ABCD) + (Mass of DE) (centre of mass of DE) ) / total mass

But I don't know how to find the masses needed...

Reply 4

ghostwalker

Original post by Electrogeek

I know that the calculation I have to do is:

( (Mass of ABCD) (centre of mass of ABCD) + (Mass of DE) (centre of mass of DE) ) / total mass

But I don't know how to find the masses needed...