Answer:
The current is 
Explanation:
From the question we are told that
The length of the segment is
The current is
The force felt is
The distance of the second wire is 
Generally the current on the second wire is mathematically represented as

Here
is the permeability of free space with value
=> 
=> 
Answer:
η = 0.667 = 66.7%
Explanation:
The efficiency of the man can be given by the following formula:
η = output/input
where,
η = efficiency of man = ?
output = potential energy gain of the box = Wh
input = work done by man = Fd
Therefore,

where,
W = weight of box = 200 N
h = height gained by box = 1 m
F = force exerted by man = 60 N
d = length of ramp = 5 m
Therefore,

<u>η = 0.667 = 66.7%</u>
Answer:
q=6.22*10^-10C
Explanation:
Two large metal plates of area 0.88 m2 face each other, 4.8 cm apart, with equal charge magnitudes but opposite signs. The field magnitude E between them (neglect fringing) is 80 N/C. Find |q|
E=α/∈, electric field within the plate
α=q/A
A=area of the plate
∈=is the permittivity
substituting , we have
The field magnitude E between them (neglect fringing)
E=q/A∈
q=EA∈
q=0.88*80*8.84*10^-12
q=6.22*10^-10C