Answer:
Velocity will be equal to 7.31 m/sec
Explanation:
We have given mass of the student m = 61 kg
Height of the water slide h = 12.3 m
Acceleration due to gravity 
Potential energy is equal to 
Work done due to friction = -5800 J
So energy remained = 7352.94-5800 = 1552.94 J
This energy will be equal to kinetic energy
So 


v = 7.13 m/sec
The total resistance is R = voltage / current
This resistance R = (L/A)r where:
r is the resistivity
L is the length of the conductor
A is the cross-sectional area of the conductor.
thus r = RA/L
You are given L; you can compute R from the voltage and current you are given; and the cross-sectional area of a round wire is (pi)(radius^2) or (pi/4)(diameter^2)
Answer:
Part a)

Part b)
this is a large potential which can not be possible because at this high potential the air will break down and the charge on the sphere will decrease.
Part C)
here we can assume the sphere is placed at vacuum so that there is no break down of air.
Explanation:
Part a)
As we know that the potential near the surface of metal sphere is given by the equation

here we have
Q = 8 C
R = 10.0 cm
now we have


Part b)
this is a large potential which can not be possible because at this high potential the air will break down and the charge on the sphere will decrease.
Part C)
here we can assume the sphere is placed at vacuum so that there is no break down of air.
Please READ Newton's first law of motion, and you'll see how nicely it explains that fact.