Answer:
C. 72
Explanation:
Transformer: A transformer is an electromagnetic device that uses the property of mutual inductance to change the voltage of alternating supply.
In a ideal transformer,
Vs/Vp = Ns/Np ............................................. Equation 1
Where Vp = primary voltage, Vs = secondary voltage, Ns = Secondary turn, Np = primary turn.
Making Ns the subject of the equation,
Ns =(Vs/Vp)Np .......................................... Equation 2
Given: Vs = 24 V, Vp = 115 V, Np = 345.
Substitute into equation 2
Ns = (24/115)345
Ns = 72 turns.
Thus the number of turns in the secondary = 72 turns.
The right option is C. 72
Answer:
reviewing the opinion of the two students we see that neither is right, since when the kinetic energy increases the potential energy decreases by the same value
Explanation:
For this exercise we must use the law of conservation of energy.
Starting point. Resting electron
Em₀ = U = eV
the potential difference and the electric field are related
V = - E d
Final point. When leaving the electric field
= K = ½ m v²
Em₀ = Em_{f}
e E d = ½ m v²
From this expression we see that when an electron moves from the initial point to the final point, the potential energy must decrease, for the total energy to be constant.
When reviewing the opinion of the two students we see that neither is right, since when the kinetic energy increases the potential energy decreases by the same value
We don't know that at all. The 3rd law says that the REaction is opposite and EQUAL to the action. We don't know where that "twice as much" comes from.
Answer:
1) Mass of the grain is
.
2) 0.08901 kg of sand would have surface area equal the surface area of the cube.
Explanation:
1) Radius of the grain,r = 64.8 µm =
Volume of the sphere =
Volume of the grain of a sand:


Density of a grain of sand = 
Mass of a grain of a sand = M


Mass of the grain is
.
2) Surface are of sphere: 
Surface area of a grain:


Length of the cube = a = 0.514 m
Total surface area of cube ,A'= 

let the number grains with area equal to total surface area of cube be x.


Volume of x number of grains :V'



Mass of
of sandL:
=
0.08901 kg of sand would have surface area equal the surface area of the cube.