Answer:
Explanation:
It is given that,
Distance between the spotlight and the wall, y = 24 m
Height of the woman, h = 2 m
The woman walks toward the building at the rate of 0.6 m/s,
In the attached figure, triangle ABC and MNC are similar. So,
............(1)
When she is 2 meters from the building. So x = 24-2 = 22 m
Differentiating equation (1) i.e.
So, her shadow is decreasing at the rate of 0.059 m/s. Hence, this is the required solution.
Answer:
The electric field carries the same mount of energy as the magnetic field
The frequency of the magnetic field is the same as the frequency of the electric field.
Explanation:
Let's analyze each option in detail:
The electric and magnetic fields have equal amplitudes. --> FALSE. In fact, the amplitudes of the electric and magnetic field are related by the equation:
where
E is the amplitude of the electric field
B is the amplitude of the magnetic field
c is the speed of light
Therefore, from the equation we see that the amplitude of the electric field is much larger than that of the magnetic field.
The electric field carries the same mount of energy as the magnetic field. --> TRUE.
The energy carried by the electric field is:
where is the vacuum permittivity.
The energy carried by the magnetic field is:
where is the vacuum permeability.
Given the following relationship:
We can write
So
which means .
The electric field carries more energy than the magnetic field. --> FALSE, because in disagreement with the calculations above.
The frequency of the magnetic field is the same as the frequency of the electric field. --> TRUE. In an electromagnetic waves, electric field and magnetic field oscillate at the same frequency.
The frequency of the electric field is higher than the frequency of the magnetic field. --> FALSE, because in disagreement with the previous statement.