Solving Spring Tasks: Plotting Graphs and Calculating Spring Constants

[leloup]

Homework Statement

Preliminary questions:

1. John's weight is 618 N. He is sitting on a bosun's chair which is suspended from a spring. John's feet are pressing vertically down on a bathroom scale which reads 45 kg. What force is John exerting on the bathroom scale?

Correct, computer gets: 441 N

2. What force is John applying to the spring?

Correct, computer gets: 177 N

The spring task:

Here is a table of the force applied to a spring and the resulting extension, Δl.

Force (N) Δl (m)
281 0.10
358 0.15
685 0.30
1012 0.45
1089 0.50

Plot a graph of Force vs. Δl.
What is the spring constant? If you don't plot a graph (or use a fitting program), you will get wrong answers. Plot the graph and see why.

Homework Equations

Not sure.

The Attempt at a Solution

I've plotted a graph, and came up with Δl = 0.4. Then I devided 177 N by 0.4, but the resulting answer wasn't correct.

 

[perpetual]

just plot the graph on excel and get the equation of the line. you will something like this y=2034x+54. the 2034 will be your spring constant

 

[haruspex]

just plot the graph on excel and get the equation of the line. you will something like this y=2034x+54. the 2034 will be your spring constant

I doubt leloup is still waiting for an answer after 8 years.