Answer:
16kg
Explanation:
This problem is borers on elasticity of materials.
according to Hooke's law, "provided the elastic limit of an elastic material is not exceeded the the extension e is directly proportional to the applied force."

where F is the applied force in N
k is the spring constant N/m
e is the extension in meters
Given data
mass m= 24kg
extensnion=15cm in meters=
=

we can solve for the spring constant k
we also know that the force F = mg
assuming

therefore

We can use this value of k to solve for the mass that will cause an extension of

