Answer:
A. 1.6 N/cm
Explanation:
spring constant = 21/13 = 1.6 N/cm
The ball with greater mass has more density
Visibly you can see that the two copper are different sizes so the mass and volume are different. No information is given about the temperature but they are side by side so you can assume they're both room temp. The density is a ratio of mass per volume. The density will remain the same unless the two are different purities or physical states.
Answer:
D.The potential energy per unit charge
Explanation:
Electric potential of a charged particle:
It is scalar quantity because it has magnitude but it does not have direction.
It is the amount of work done required to move a unit positive charge from reference point to specific point in the electric field without producing any acceleration.
Mathematical representation:

Where W= Work done
= Unit positive charge
Other formula to calculate electric field:

Where K=
It can be defined as potential energy per unit charge.
Hence, option D is true.