[fGDu]

Hi I'm a bit stuck on question 5 on this paper:

http://eiewebvip.edexcel.org.uk/Repo...e_20070125.pdf

The mark scheme can be found here:

http://eiewebvip.edexcel.org.uk/Repo...s_20070314.pdf

At first I didn't consider the tension in RB, and I got an answer which was similar to the required answer but not quite the same. I looked on the mark scheme and saw that there was tension to consider in both RB and RA, but I couldn't really make sense of the method they used.

[mikelbird]

Since it is a smooth ring the tension is the same throughout the string. If you consider just the ring the the tension in both parts is away from the ring. Then all that has been done is to resolve horizontally (using the standard expression for radial acceleration) and vertically (where the component of the tension in string AR balances the weight of the ring). From there onwards it is simply algebra...does that give you any problems??

[fGDu]

(Original post by mikelbird)
Since it is a smooth ring the tension is the same throughout the string. If you consider just the ring the the tension in both parts is away from the ring. Then all that has been done is to resolve horizontally (using the standard expression for radial acceleration) and vertically (where the component of the tension in string AR balances the weight of the ring). From there onwards it is simply algebra...does that give you any problems??

The algebra is fine for me, I just didn't understand that the tension would be the same throughout the string.