Answer: 5 Newton
Step-by-step explanation:
We know that the Hooke's law states that the force 'F' needed to stretch or compress a spring by some distance 'a' is proportional to that distance .
, where c is the spring constant.
Given: A spring has spring constant 0.3 m/newton.
The force is necessary to stretch the spring by 1.5 meters is given by :-

Hence, the force is necessary to stretch the spring by 1.5 meters = 5 Newton .