If it is s-t graph , point is c
if it is v-t graph , point is e
Answer:

Explanation:
Given data:
first case
Distance of electric field from center of sphere is r_1 <R
Electric field at r_1< R

second case
Distance of electric field from centre of sphere is r_1 < 2R
Electric field at r_1< 2R

so, we have

Answer:

Explanation:
The final velocity is given by the following kinematic equation:

Here,
is the initial velocity, a is the body's acceleration and t is the motion time. We have to convert the time to seconds:

Now, we calculate the final velocity:
