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HallsofIvy

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I don't understand the problem. YOu state "you will fly through the air over a 15-ft wall and land safely in a net", then ask "is it possible to make it over the wall". Didn't you just say it was??

I guess the problem is to find the potential energy stored in the spring when it is compressed, convert that to kinetic energy as you leave the cannon to find your initial speed and then use kinematics to determine if the maximum point of the trajectory really is more than 15 ft. To do that, you need to know the "spring constant" for the spring.

That's probably the point of "When you hang on the spring w/o touvhing the ground it stretches by 2-ft." but, while I know

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Andrew Mason

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The condition for success is:yellowstriker said:

Spring potential energy > mgh + KE

So:

[tex]\frac{1}{2}kD^2 > mgh[/tex]

To determine K, we know that it stretches 2 feet due to your weight so:

kd=mg where d =2 so k = mg/2

I think you will find that the inequality is satisfied leaving more than enough for the needed Kinetic energy to provide horizontal travel.

AM

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