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# Mechanics 3 - Review Exercise 1 Q37 watch

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1. I have just come across this pickle of a question, the likes of which I have not down before !__! ....I gave it a shot, but I am not sure as to how to take the horizontal component of the string when it is extended into account, so I get the wrong value of extension, moley....anywhoo..

37) A light elastic string of natural length 5m and modulus 4N has one end fixed to a point O on level ground. To the other end of the string is attached a ball of mass 0.5kg, which is projected vertically upwards from O with speed um/s

(a) Find u, given that the ball first comes to instantaneous rest when it reaches a height of 10m above the ground.

ah smudge it, what the hell am I doing, the question doesn't say that the string is flat along the ground...is projected from O.

I am leaving this here, as I now want to know how the question would be answered if the ball was indeed projected 5 metres from O with the string flat...how would I go about answering the question?

2. If the particle was projected like that, then it would be under the effect of a "central force" due to the tension in the string. This force will act at the particle in a direction towards O. However, here you'd also need to take weight into account which makes the problem considerably harder.
3. PM widowmaker he's the mechanics king
4. (Original post by goku999)
PM widowmaker he's the mechanics king
lol, I sent him a pm. He understands it though.

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