Answer:
[tex]m=1.53kg[/tex]
Explanation:
To solve this problem we use the Hooke's Law:
[tex]F=k*\Delta x[/tex] (1)
F is the Force needed to expand or compress the spring by a distance Δx.
The spring stretches 0.2cm per Newton, in other words:
1N=k*0.2cm ⇒ k=1N/0.2cm=5N/cm
The force applied is due to the weight
[tex]F=mg[/tex]
We replace in (1):
[tex]mg=k*\Delta x[/tex]
We solve the equation for m:
[tex]m=k*\Delta x/g=5*3/9.81=1.53kg[/tex]
