I think it’s true but i’m not too sure
Answer:
D. They don't require a medium to travel through.
Explanation:
Electromagnetic waves and mechanical waves are both types of waves. Electromagnetic waves are waves that arise from the combination of electric and magnetic fields while mechanical waves are waves that arise as a result of transfer of energy via matter.
One major difference between these two types of waves is that electromagnetic waves such as light waves, radiowaves etc. do not need a medium to travel i.e. they can travel through a vacuum, while on the other hand, mechanical waves such as sound waves need a medium to travel.
To solve this problem it is necessary to apply the concepts related to the condition of path difference for destructive interference between the two reflected waves from the top and bottom of a surface.
Mathematically this expression can be described under the equation
Where
n = Refractive index
t = Thickness
In terms of the wavelength the path difference of the reflected waves can be described as
Where
\lambda = Wavelenght
Equation the two equations we have that
Our values are given as
Wavelength of light
Therefore the minimum thickness of the oil for destructive interference to occur is approximately 34.0 nm
Answer:
In waves distance is measured by wave length and time is measured by frequency or period.
velocity ratio=wave length multiply by frequency.
HENCE, if the same wave travels for 2 econds its frequency will be 2Hz.
Explanation:
Answer:
c = e > b = d > a
Explanation:
Given vectors are all unit vectors, therefore they have a magnitude of 1
<h3>Let a, b be two vectors and magnitude of cross product of these two vectors is (magnitude of a) × (magnitude of b) × (sine of angle between these two vectors)</h3>
As all are unit vectors their magnitude is 1 and therefore in this case the cross product between any two vectors depends on the sine of angle between those two vectors
In option a as both the vectors are same, the angle between them will be zero and sin0° will also be 0
In option b angle between those two vectors is 135° and sin135° is 1 ÷ √2
In option c angle between those two vectors is 90° and sin90° is 1
In option d angle between those two vectors is 45° and sin45° is 1 ÷ √2
In option e angle between those two vectors is 90° and sin90° is 1
So by comparison of magnitudes of cross products in each option, the order will be c = e > b = d > a