Centre Of Mass

Question 1

For this q , where would it exceed the boundary ?

Answer 1

Basically remember to thing of it as a COORDINATE POINT

Yes where you thought orinally but , the centre of mass must act WITHIN THE DIMENSIONS of the shape max, it’s not possible to act OUTSIDE the shape where there IS NO mass

So you thought outside shape, whereas here, the x value is still in the shape, and y is outside shape

This CAN WORK bevause it’s WITHIN THE total boundary of the shape, but the centre of msss can’t act outside

So like celotape, centre of msss can act in the middle where there is no tape, which is what this a is askign, but can’t act OUTSIDE

Do not lack

Question 2

Remember, where can centre of msss act in a shape

Answer 2

ANYWHERE WITHIJ THE BOUNDARY OF THE TOTAL DIMENSIONS, NOWHERE THAT exceeds the shape for sure

Now look at x and y separately and look at LENGTHS not area

So y 1 unit up for P and 2 for Q, so max would be 3 and under, it can’t be more than 3, not possible

But if you pout thst in inequality you end up taking bigger anyways so it’s calm

For x there’s 2 for P and 1 for A, centre of mass can’t exceed 3, thus must be in between !

Question 3

If you’re still not convinced, do both inequalities and you’ll see it ends up working

Question leaves an empty space, they probably wanting you to go there don’t worry!

Answer 3

Don’t stress

Question 4

What’s the y centre of mass for tall rectangle DONT LACK

Answer 4

chekc talked cooridnate and divide by 2, not what it LOOKS TO BE

Question 5

No need to think twice, when hanging , where will ALWAYS THE CENTRE OF MASS BE

Answer 5

DIRECTLY BELOW THE HANGING POINT

Question 6

Also when you found the centre of mass FOR ONE SYSTEM, and change the orientation, will the position of centre of mass change?

Answer 6

NO THE POSITION IS ALWAYS RHE SAME

So if it is 10 from x , it will ALWAYS BE 10 FROM X NO MATTER HOW YOU DANGLE IT

And the com will always act below the point of suspension, don’t lack!

Question 7

If you don’t have the means to find volume, what should you do

Remember if densities are different havr to take this into account too

Answer 7

Gonna seem wrong but just do AREA, like volume, and assume the thickness is the same so you are doing volume