Need help on a mechanics question (1 Viewer)

tickboom

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Does anybody have any ideas for part ii)? I can show it for n=3, but can't work out how to show it in general. I tried induction but it didn't seem to work for me.

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Drdusk

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Does anybody have any ideas for part ii)? I can show it for n=3, but can't work out how to show it in general. I tried induction but it didn't seem to work for me.

View attachment 29542
Don't see why you would have to use induction.

Using you get



Calculating avg speed you get





Now we know that v < v_avg < u because the speed is constantly decreasing so it must be less than the start speed but greater than the instantaneous speed.



Simplifying further

 

tickboom

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Don't see why you would have to use induction.

Using you get



Calculating avg speed you get





Now we know that v < v_avg < u because the speed is constantly decreasing so it must be less than the start speed but greater than the instantaneous speed.



Simplifying further

Brilliant! Thanks so much!
 

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