How Do You Calculate Spring Constant and Package Weight?

AI Thread Summary
To calculate the spring constant and package weight, the initial position of the pointer without a package is 23 mm. The weight of the third package is determined to be 45 N. The user initially attempted to use the formula 130 N = -k * 20 mm but later found the correct answers independently. The discussion highlights the importance of understanding the relationship between force and displacement in spring mechanics. Ultimately, the user resolved their queries without further assistance.
queenspublic
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1. Problem

A spring with a pointer attached is hanging next to a scale marked in millimeters. Three different packages are hung from the spring, in turn, as shown below.

07_39.gif


(a) Which mark on the scale will the pointer indicate when no package is hung from the spring?
(a) ? mm

(b) What is the weight W of the third package?
(b) ? N

2. Attempt at a solution

240 N - 110 N = 130 N
60 mm - 40 mm = 20 mm

130 N = -k * 20 mm <-- Is this formula correct? If not, how do I find the answers to (a) and (b)?
k = -6.5
 

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Never mind. I found the answers.

(a) 23 mm
(b) 45 N

Thanks for nothing. lol.
 
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