Answer:
a. 2 Hz b. 0.5 cycles c . 0 V
Explanation:
a. What is period of armature?
Since it takes the armature 30 seconds to complete 60 cycles, and frequency f = number of cycles/ time = 60 cycles/ 30 s = 2 cycles/ s = 2 Hz
b. How many cycles are completed in T/2 sec?
The period, T = 1/f = 1/2 Hz = 0.5 s.
So, it takes 0.5 s to complete 1 cycles. At t = T/2 = 0.5/2 = 0.25 s,
Since it takes 0.5 s to complete 1 cycle, then the number of cycles it completes in 0.25 s is 0.25/0.5 = 0.5 cycles.
c. What is the maximum emf produced when the armature completes 180° rotation?
Since the emf E = E₀sinθ and when θ = 180°, sinθ = sin180° = 0
E = E₀ × 0 = 0
E = 0
So, at 180° rotation, the maximum emf produced is 0 V.
This is a concept of momentum. In equation, momentum is the product of force and distance. When a ball is thrown, its force is constant all throughout unless disturbed by an external force. Therefore, force is the constant of proportionality that relates momentum with distance. When you block a ball from a given distance, you would feel the great force on your hand. In order to reduce the force, you have to follow the direction of the force in order to minimize the impact. By doing this, you gradually decrease the momentum of the ball.
Answer:
Please refer to the figure.
Explanation:
The magnitude of the magnetic field can be found by Biot-Savart Law. We should divide the loop into four components. Each component has a similar solution but their directions are quite different.
The directions can be found by right-hand rule. Point your index finger into the direction of current, point your middle finger towards the target point (0,0,a). Your thumb will show you the direction of magnetic field.
Answer:
Explanation:
We can use the conservation of the angular momentum.


Now the Inertia is I(professor_stool) plus mR², that is the momentum inertia of a hoop about central axis.
So we will have:

Now, we just need to solve it for ω.

I hope it helps you!
example force. because you can say" I applied 3 newtons downward to the floor".
force has magnitude and direcion