Answer:
Explanation:
N=Rotor Speed in Revolution per minute(rpm)
for P=4 and N=3600, f comes out to be 120 Hz.
So frequency of voltage produced is 120 Hz. But this is not practical. Generally 4-Pole generator has N=1500rpm(for 50 Hz) or 1800rpm for 60 Hz. Two pole generator can have N=3600rpm(f=60Hz).
The most practical situation is generator having N=3600Hz with 2 Poles.
Hope It will be helpful!!!
Answer:

Explanation:
From the question we are told that:
Mass 
Velocity 
Angular Velocity 
Generally the equation for Kinetic Energy is mathematically given by



For the part a) we need only the momentum of the box and we have the data to find it.
Momentum is given by,

where clearly, p is the momentum, m the mass of the box and v is the velocity.
Substituting,

For part b) we need an analysis of the situation. We understand that the box on a surface that has no friction will continue to rotate at the same speed previously defined. The box can only stop with friction, so,

<em>It is the same that part a)</em>
Answer: 0.006in/s
Explanation:
Let the rate at which air is being blown into a spherical balloon be dV/dt which is 1.68in³/s
Also let the rate at which the radius of the balloon is increasing be dr/dt
Given r = 4.7in and Π = 3.14
Applying the chain rule method
dV/dt = dV/dr × dr/dt
If the volume of the sphere is 4/3Πr³
V = 4/3Πr³
dV/dr = 4Πr²
If r = 4.7in
dV/dr = 4Π(4.7)²
dV/dr = 277.45in²
Therefore;
1.68 = 277.45 × dr/dt
dr/dt = 1.68/277.45
dr/dt = 0.006in/s