Thanx for answer.
Yes, the spreing compresess. For example we have a 1 kg object with no spring. How would we calculate the force when the spring is betwen object and weight?
We put object on weight ang get a mass. What would that mass be if we put a spring between object and weigt, so that the spring woul shrink to half its original size?
For light it is said it has no volume and also it it waves of electric and magnetic field. But for electric and magnetic field you need space? So can they both be at the same time?
No I meant electric field. I know there is potencial diffrence between ends, but ther is also electric field insede wire. And electric fieled is a field so it is evrywhere, just sometimes its value might be zero.