Answer: 5.41 V
Explanation:in order to explain this result we have to use the Ohm law given by:
ΔV=R*I where R is the resistance which is equal R= ρ*L/A . ρ is the resistivity, L the length of the wire and A is the cross section. I is the current.
Then we have
ΔV=ρ*L*I/A= 1.68 * 10^-8 Ωm*93.4 m*72.5A/2.1* 10^-5 m^2=5.41 V
Explanation:
i think C . it is twice the size of the object
Answer:
F = 2π I R B
Explanation:
The magnetic force is described by the equation.
F = q v x B = i L x B
Where i is the current, L is a vector that points in the direction of the current (length) and B is the magnetic field.
This equation can be used in scalar form and the direction of the force found by the right hand ruler, the thumb goes in the direction of L, the fingers extended in the direction of B and the palm of the hand indicates the direction of the force if the load is positive
F = i L B sin θ
In this case the wire is in the xy plane and the z-axis field whereby they are perpendicular, θ = 90º and sin 90 = 1
F = i L B
The loop length is
L = 2π R
F = i 2π R B
F = 2π I R B
The force is in the loop
Complete question is;
Shoveling snow can be extremely taxing since the arms have such a low efficiency in this activity. Suppose a person shoveling a sidewalk metabolizes food at the rate of 800 W. (The efficiency of a person shoveling is 3%.)
(a) What is her useful power output? (b) How long will it take her to lift 3000 kg of snow 1.20 m? (This could be the amount of heavy snow on 20 m of footpath.) (c) How much waste heat transfer in kilojoules will she generate in the process?
Answer:
A) P_out = 24 W
B) t = 1470 s
C) Q = 1140.72 KJ
Explanation:
We are given;
Input Power; P_in = 800 W
Efficiency; η = 3% = 0.03
A) Formula for efficiency is;
η = P_out/P_in
Making P_out the subject, we have;
P_out = η•P_in
P_out = 0.03 × 800
P_out = 24 W
B) We know that;
Power = work done/time taken
Thus;
P_out = mgh/t
We are given;
m = 3000 kg
h = 1.20 m
Thus, time is;
t = (3000 × 9.8 × 1.2)/24
t = 1470 s
C) amount of heat wasted is calculated from;
Q = (P_in - P_out)t
Q = (800 - 24) × 1470
Q = 1,140,720 J
Q = 1140.72 KJ
Answer:
0.786 Hz, 1.572 Hz, 2.358 Hz, 3.144 Hz
Explanation:
The fundamental frequency of a standing wave on a string is given by
where
L is the length of the string
T is the tension in the string
is the mass per unit length
For the string in the problem,
L = 30.0 m
T = 20.0 N
Substituting into the equation, we find the fundamental frequency:
The next frequencies (harmonics) are given by
with n being an integer number and f being the fundamental frequency.
So we get:
