Bathroom scale being compressed but jumping on itby kavipach Tags: bathroom, compressed, jumping, scale 

#1
Jul1709, 12:49 AM

P: 20

1. The problem statement, all variables and given/known data
If you stand on a bathroom scale, the spring inside the scale compresses 0.55mm, and it tells you your weight is 760N. Now if you jump on the scale from a height of 1.3 m, what does the scale read at its peak? 



#2
Jul1709, 12:55 AM

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P: 6,213

What are your thoughts on the question? Post your attempt.




#3
Jul1709, 01:04 AM

P: 20

well i tried a few things... i found the persons mass which is 77.55kg.Since F=ma,and we have m, i tired using kinamatics to find a but finding the velocity of the person just before impact. Then i got stuck. I dont know how to go about this question.




#4
Jul1709, 01:09 AM

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Bathroom scale being compressed but jumping on it 



#5
Jul1709, 01:11 AM

P: 20

ya hookes law...F=kx.




#6
Jul1709, 01:11 AM

P: 20

where k equals spring constant and x equals displacment




#7
Jul1709, 01:14 AM

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So can you find the spring constant,k using the information in the first line of the question? 



#8
Jul1709, 01:18 AM

P: 20

according to this the constant equals to 1381818.2 is this right




#9
Jul1709, 01:22 AM

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P: 6,213

So second line now. If the person is at 1.3m in the air, what type of energy does he have? This energy is converted into the energy needed to compress the spring a displacement,x, at the peak. 



#10
Jul1709, 01:24 AM

P: 20

potential energy?




#11
Jul1709, 01:26 AM

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#12
Jul1709, 01:33 AM

P: 20

The formula for gravitational potential energy is U=mgy where u equals the p.e, m equals mass and y is the displacement. the formula for the energy storedd in a spring is U=1/2kx^2




#13
Jul1709, 01:36 AM

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gravitational p.e. = energy stored in the spring. Can you find the compression,x for the scale now? 



#14
Jul1709, 01:38 AM

P: 20

ya i think i can..thanks for all the help..your a life saver



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