B, is the answer to the question
A book weighing 15 N sits on a desk. What is the force the desk is exerting back on the book?
1 answer:
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Faraday's law allows us to find the magnetic field that produces the emf in the rotating system is:
- The magnetic field is: B = 0.424 T
Faraday's law of induction states that when the magnetic flux changes in time, an induced electromotive force is produced.
fem =
where fem is the induced electromotive force and Ф the flux,
The magnetic flux is the scalar product of the field and the area.
In this case we have several turns, so the expression remains.
fem =
Indicate that the turns rotate at a constant frequency, therefore we can use the uniform rotational motion ratio.
θ = w t
We substitute
the maximum induced electromotive force occurs when the sine function is ±1
fem = N B A w
They indicate that the fem = 24 V, the number of the turn is N = 20, the area is A = 75 cm² = 75 10⁻⁴ m² and the frequency f = 60 Hz
Frequency and angular velocity are related.
w = 2π f
We substitute.
fem = N B A 2π f
Let's calculate.
B = 24 / 2pi 20 75 10-4 60
B = 0.424 T
In conclusion, using Faraday's law we can find the magnetic field that produces the emf in the rotating system is:
- The magnetic field is; B = 0.424 T
Learn more about Faraday's law here: brainly.com/question/24617581
Given:
m = 0.14 kg
v = 18 m/s
To find:
Kinetic energy= ?
Explanation:
Kinetic energy of the object is possessed when the object is in motion. It is define as the work done required to accelerate a body from rest to motion. Unit of energy is Joule and it is same as unit of work done. Energy is nothing but the capacity to do work.
Solution:
Kinetic energy of the ball is given by,
Kinetic energy =
m = 0.14 kg
v = 18 m/s
Kinetic energy =
Kinetic energy = 226.8 Joule