Let two concentric spheres O be uniformly charged. The radii of the two spheres are R1 and R2 respectively (R2>R1). The charge on the inside is q and the charge on the outside is Q . a. Calculate the electric field strength at a point r at a distance r from the center of O (know R1 < r < R2)
b. Calculate the potential difference between the two spheres

Is a  vector quantity  that refers to "the rate at which an object changes its position." imagine a person moving rapidly - one step forward and one step back - always returning to the original starting position. while this might result in a frenzy of activity, it would result in a zero velocity. because the person always returns to the original position, the motion would never result in a change in position. since velocity is defined as the rate at which the position changes, this motion results in zero velocity. if a person in motion wishes to maximize their velocity, then that person must make every effort to maximize the amount that they are displaced from their original position. every step must go into moving that person further from where he or she started. for certain, the person should never change directions and begin to return to the starting position.

Scientific classification

What are your choices. i believe it might be mitochondria but i will know for sure when i see the choices. let me know okay i'm happy to answer