As the parachutist is descending at a steady rate
we can conclude that

Acceleration indicates the change in velocity
given the constant velocity in this scenario

Thus, in this situation, we find the acceleration to be zero
It’s understood from Newton's second law

where a is equal to 0


Here, the force due to gravity
equals the force due to buoyancy
Hence, we can deduce

therefore

as such the upward force is counteracted by the downward force.
Answer:
a
The density of volume charge is 
b
The density of surface charge is 
Explanation:
The question states that
The radius measures R
The length is L
The speed is v
The ion count per unit volume is n
The charge per ion is q
The surface thickness of the cylinder is 
The volume charge density is mathematically expressed as
The surface charge density is mathematically expressed as

substituting for 

