Answer:
(a) The self inductance, L = 21.95 mH
(b) The energy stored, E = 4.84 J
(c) the time, t = 0.154 s
Explanation:
(a) Self inductance is calculated as;

where;
N is the number of turns = 1000 loops
μ is the permeability of free space = 4π x 10⁻⁷ H/m
l is the length of the inductor, = 45 cm = 0.45 m
A is the area of the inductor (given diameter = 10 cm = 0.1 m)

(b) The energy stored in the inductor when 21 A current ;

(c) time it can be turned off if the induced emf cannot exceed 3.0 V;

Answer:
f=171.43Hz
Explanation:
Wave frequency is the number of waves that pass a fixed point in a given amount of time.
The frequency formula is: f=v÷λ, where <em>v</em> is the velocity and <em>λ</em> is the wavelength.
Then replacing with the data of the problem,
f=
f=171.43
f=171.43 Hz (because
, 1 hertz equals 1 wave passing a fixed point in 1 second).
<h2>It will take 0.125 seconds to reach the net.</h2>
Explanation:
Initial speed, u = 34 ft/s = 10.36 m/s
Acceleration, a = -9.81 m/s²
Displacement, s = Final height - Initial height = 8 - 4 = 4 ft = 1.22 m
We have equation of motion, s = ut + 0.5 at²
Substituting
s = ut + 0.5 at²
1.22 = 10.36 x t + 0.5 x -9.81 x t²
4.905t² - 10.36 t + 1.22 = 0
t = 1.99 s or t = 0.125 seconds
Minimum time is 0.125 seconds.
It will take 0.125 seconds to reach the net.
Hello!
A stretched spring has 5184 J of elastic potential energy and a spring constant of 16,200 N/m. What is the displacement of the spring ?
Data:



For a spring (or an elastic), the elastic potential energy is calculated by the following expression:

Where k represents the elastic constant of the spring (or elastic) and x the deformation or displacement suffered by the spring.
Solving:









Answer:
The displacement of the spring = 0.8 m
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I Hope this helps, greetings ... Dexteright02! =)