Answer:
a. E = 86.36 x 10⁻³ V/m = 86.36 mV/m
b. ρ = 3.6 x 10⁻⁷ Ωm
Explanation:
a.
The electric field in terms of the voltage is given by the following formula:
E = V/d
where,
E = Electric Field in the Wire = ?
V = Potential Difference = 3.8 V
d = distance between the points = 44 m
Therefore,
E = 3.8 V/44 m
<u>E = 86.36 x 10⁻³ V/m = 86.36 mV/m</u>
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b.
Now, from Ohm's Law:
V = IR
R = V/I
where,
R = Resistance of wire = ?
I = Current = 3 A
Therefore,
R = 3.8 V/3 A
R = 1.27 Ω
Now, the resistance of a wire can be given as:
R = ρL/A
where,
ρ = resistivity of material = ?
L = Length = 44 m
A = Cross-sectional area = πr² = π(0.002 m)² = 1.25 x 10⁻⁵ m²
Therefore,
1.27 Ω = ρ*44 m/1.25 x 10⁻⁵ m²
(1.27 Ω)(1.25 x 10⁻⁵ m²)/44 m = ρ
<u>ρ = 3.6 x 10⁻⁷ Ωm</u>
Given data
*The given 4th harmonic frequency is 31.5 Hz
The fundamental frequency is calculated as

Hence, the fundamental frequency is 7.875 Hz
Answer:
7772.72N
Explanation:
When u draw your FBD, you realize you have 3 forces (ignore the force the car produces), gravity, normal force and static friction. You also realize that gravity and normal force are in our out of the page (drawn with a frame of reference above the car). So that leaves you with static friction in the centripetal direction.
Now which direction is the static friction, assume that it is pointing inward so
Fc=Fs=mv²/r=1900*15²/55=427500/55=7772.72N
Since the car is not skidding we do not have kinetic friction so there can only be static friction. One reason we do not use μFn is because that is the formula for maximum static friction, and the problem does not state there is maximum static friction.