Answer:
Velocity of the electron at the centre of the ring, 
Explanation:
<u>Given:</u>
- Linear charge density of the ring=

- Radius of the ring R=0.2 m
- Distance of point from the centre of the ring=x=0.2 m
Total charge of the ring

Potential due the ring at a distance x from the centre of the rings is given by

The potential difference when the electron moves from x=0.2 m to the centre of the ring is given by

Let
be the change in potential Energy given by

Change in Potential Energy of the electron will be equal to the change in kinetic Energy of the electron

So the electron will be moving with 
Answer:
A. MA=force output/force input
Explanation:
mechanical advantage is the ratio of the load to the effort
Answer:
Isolated or Closed system, both are correct
Its good for a scientist to be skeptical because they dont willingly accept new ideas without thoroughly going over the research themselves and attempting to disprove a theory. skeptical scientists often reveal new information through doing their own examinations of a concept, which is why they are valuable scientists
Answer:
light doesn't need a medium through which to travel because the speed of light is experimentally constant