Answer:
The workdone is
Explanation:
From the question we are told that
The potential difference is 
Generally the charge on
is 
Generally the workdone is mathematically represented as

=>
=>
136lb?? I'm so confused rn!! I'm super sorry!!
We don't know that at all. The 3rd law says that the REaction is opposite and EQUAL to the action. We don't know where that "twice as much" comes from.
Answer:
a) 3.33 ns
b) Water distance = 0.75 m
Glass distance = 0.66 m
Diamond distance = 0.41 m
Explanation:
We take the speed of light, c = m/s.
Speed = distance/time
Time = distance/speed
a)

t = 3.33 ns
b)
Refractive index, n = speed of light in vacuum / speed of light in medium





Thus, the distance traveled in the same time is numerically equal to the reciprocal of the refractive index.
For water n = 1.333
d = 1/1.333 = 0.75 m
For glass n = 1.517
d = 0.66 m
For diamond n = 2.417
d = 0.41 m
mass of the ball m = 0.63 kg
initial height h = 1.8 m
final height h ' = 3.03 m
initial speed v = 7.09 m / s
final speed v ' = 4.21 m / s
Let the work done on the ball by air resistance W = ?
we know from law of conservation of energy ,
total energy at height h + work done by air = total energy at height h '
mgh + ( 1/ 2) mv^ 2 + W = mgh ' + ( 1/ 2) mv'^ 2
0.630*9.8*1.8 + 0.63*7.09^2 + W = mgh ' + ( 1/ 2) mv'^ 2
From there you can find W
if there is negative sign indicates it work opposite direction to motion