Answer:
2665.6 N/m
Explanation:
The potential energy of elevator will convert to PE of the spring
Here,
m=8.5 kg
h=4.0 m
g=9.8m/s2
PE of elevator =mgh = 8.5×9.8×4.0=333.2 J
PE of spring = 1/2 k [tex]x^{2}[/tex]
where,
k=? (to be found)
x= 0.5 m (distance by compressing the spring)
==> PE of spring = 1/2× k× 0.5×0.5 = 0.125k
Since .
PE of elevator = PE of the spring
==> 333.2 =0.125k
==> k = 333.2÷0.125=2665.6 N/m