Answer:
k = 40 N/m
Explanation:
A spring's energy is given:

U is the energy in the spring, k is the spring constant and x is the spring displacement.
We are told that the spring stores 5J of energy, therefore, U = 5J. We are also told that the spring is compressed by 0.5m, so the spring x = 0.5m

k = 40 N/m
Hope this helps!
In an extremely simplified explanation,
What happens is that the steam (heat) that is generated by the burning of coal is used to rotate the motor of the steam engine.
Color is what scientist use to determine the temperature of a star!
hope this helps!
There can be mental health effects and psychological dependence