Answer:
- The gravity does a work of - 117.6 Joules.
- The tension does not do work as the force is perpendicular to the direction of motion at any point in the trajectory.
Explanation:
The work done by the gravity simply is the difference in gravitational potential energy multiplied by -1:

where m is the mass of the ball, g is the acceleration due to gravity,
is the final height and
is the initial height.
So, if the radius is 2.00 m, then the difference of height will be 4 meters:



As the tension is perpendicular to the velocity of the ball, the force is always perpendicular to the direction of motion. So, the differential of work will be:

PART A)
Electrostatic potential at the position of origin is given by

here we have



now we have


Now work done to move another charge from infinite to origin is given by

here we will have

so there is no work required to move an electron from infinite to origin
PART B)
Initial potential energy of electron




Now we know



now by energy conservation we will have
So here initial total energy is sufficient high to reach the origin
PART C)
It will reach the origin
Answer:
Explanation:
The electron has a negative charge. Proton is positive and neutron is neutral.