If the length of a 26cm spring increases to 46cm when a 8kg weight is hanging from it, what is the spring's constant?

1 Answer
Mar 3, 2018

392.4N/m

Explanation:

the spring constant is the direct proportion between:

the force applied on the string

and the extension of the string when the force is applied on it.

they have the relationship

F=ke

where

F is the force in newtons, N

k is the 'spring constant' in newtons per metre, N/m

and e is the extension in metres, m.

here, the force is that applied on the 8kg weight.

W=mg

where W is weight (force due to gravity)

m is mass

and g is gravitational field strength.

on Earth, g9.81 newtons per kilogram, N/kg.

the force applied is 8kg 9.81N/kg

which is 78.48 N.

the extension is from 26cm to 46cm.

46cm 26cm =20cm

20cm is 20100m, which is 0.2m.

F=ke

78.48N =k0.2m

k=(78.480.2) N/m

78.480.2=78.485=392.4

k=392.4 N/m