Why does a compressed spring throw up a load?

If the spring is compressed, then it will straighten: the particles that come too close to each other are repelled. Particles of any substance are at some distance from each other and interact, that is, they are attracted and repelled. Therefore, the compressed spring throws up the load.

Remember: The process of learning a person lasts a lifetime. The value of the same knowledge for different people may be different, it is determined by their individual characteristics and needs. Therefore, knowledge is always needed at any age and position.