The average current density in the wire is given by:
where I is the current intensity and A is the cross-sectional area of the wire.
The cross-sectional area of the wire is given by:
where r is the radius of the wire. In this problem, , so the cross-sectional area is
and the average current density is
Complete Question
The complete question is shown on the first uploaded image
Answer:
The velocity is in positive x -direction
The speed is
Explanation:
From the question we are told that
The distance from the house to truck is D = 20 m
The distance traveled back to retrieve wind-blown hat is d = 15
The distance from the wind-blown hat position too the truck is k = 20 m
The total time taken is t = 75 s
Generally when calculating the displacement the Justin's backward movement to collect his wind - blown hat is taken as negative
Generally Justin's displacement is mathematically represented as
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Generally the average velocity is mathematically represented as
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Generally the distance covered by Justin is mathematically represented as
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Generally Justin's average speed over a 75 s period is mathematically represented as
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