Answer:
400 J
Explanation:
Work is done when a force that is applied to an object moves that object.
The work is calculated by multiplying the force by the amount of movement of an object
W = F * d
here the man has to work against the gravitational field. (against his weight)
F =100 N
Work done = F * d
= 100 * 4
= 400 J
Answer:
- Work done is maximum when the movement of object is in line and direction of force.
OR
- Work done is maximum, when displacement takes place along the direction of force.
- Work done is given by the equation
W = F.S
<em> W = F. S cos Θ</em>
<em>When cos Θ = 0° ; cos 0 = 1</em>
Twice the amplitude of each wave
Answer:
Their speed in a vacuum is a constant value.
Explanation:
Electromagnetic waves consits of oscillations of electric field and magnetic field. The oscillations of these fields occur in a direction perpendicular to the direction of propagation of the waves, so they are transverse wave. Electromagnetic waves, contrary to mechanical waves, do not need a medium to propagate, so they can also travel through a vacuum. In a vacuum, their speed is constant and has always the same value, the speed of light:
Answer:
if this surface has a higher index than in the medium where the light travels, the reflected wave has a phase change of 180º
Explanation:
When a ray of light falls on a surface if this surface has a higher index than in the medium where the light travels, the reflected wave has a phase change of 180º this can be explained by Newton's third law, the light when arriving pushes the atoms of the medium that is more dense, and these atoms respond with a force of equal magnitude, but in the opposite direction.
When the fractional index is lower than that of the medium where the reflacted beam travels, notice a change in phase.
Also, when light penetrates the medium, it modifies its wavelength
λ = λ₀ / n
We take these two aspects into account, the condition for contributory interference is
d sin θ = (m + 1/2) λ
for destructive interference we have
d sin θ = m λ
in general this phenomenon is observed at 90º
2 d = (m +1/2) λ° / n
2nd = (m + ½) λ₀
