Answer:
a) 0.142mH
b) 14mV
Explanation:
the complete answer is:
(a) Calculate the self-inductance of a solenoid that is <ghtly wound with wire of diameter 0.10 cm, has a cross-sec<onal area of 0.90 cm2 , and is 40 cm long. (b) If the current through the solenoid decreases uniformly from 10 to 0 A in 0.10 s, what is the emf induced between the ends of the solenoid
a) the self inductance of a solenoid is given by:

μo: magnetic permeability of vacuum = 4\pi*10^{-7}N/A^2
A: cross sectional area = 0.9cm^2=9*10^{-5}m
L: length of the solenoid = 40cm = 0.4m
The N turns of the wire is calculated by using the diameter of the wire:
N = (40cm)/(0.10cm)=400
By replacing in the formula you obtain:

the self inductance is 1.42*10^{-4}H = 0.142mH
b) to find the emf you can use:

the emf induced is 14mV
Hello.
Streamlined objects are objects that rudeces ari resisternece.
Some objects are
1. ari
2. water
3. solor cars
4. some land
Have a nice day
Answer:
Let the mass of the book be "m", acceleration due to gravity be "g", velocity be "v" and height be "h".
Now if we are holding a book at a certain height (h), <em><u>the potential energy will be maximum which is equal to mass× acceleration due to gravity× height (= mgh)</u>.</em>
(Remember: kinetic energy =0)
Now we consider that the book is dropped, in this case a force will act downward towards the centre of the earth, <em><u>Force= mass× acceleration due to gravity (F=mg)</u></em>. It is equal to the weight of the book.
While the book is falling, the potential energy stored in the book converts into kinetic energy and strikes the floor with <em><u>the maximum kinetic energy= (1/2)×mass×velocity² (=1/2mv²)</u>.</em>
(Remember: kinetic energy=0)
Due to this process the whole energy is conserved.
As the potential energy decreases kinetic energy increases.
Answer:
M = 50 kg / sec * 60 sec = 3000 kg water that falls
PE = M g h initial potential energy of water
PE = 3000 kg * 9.8 m/s^2 * 20 m = 588,000 joules of energy lost