Answer:
correct option is B. 1.39
Explanation:
given data
angle of incidence (θ) = 54.2 degrees
to find out
index of refraction of the glass
solution
we know that here reflected beam is completely polarized
so angle of incidence = angle of polarized ....................1
for reflective index we apply here Brewster law that is
μ = tan(θ) ...............2
put here θ value we get
μ = tan(54.2)
μ = 1.386
so correct option is B. 1.39
Answer:
Explanation:
The acceleration of the train is given by:
where:
u = 5 m/s is the initial velocity of the train
v = 45 m/s is the final velocity of the train
t = 8 s is the time taken for the train to increase the velocity
Substituting numbers into the formula, we find
Power = Work/Time =(Force* Displacement)/Time
Power = (100N* 10m)/10s = 100 Watts
Answer:
The correct answer is a. Both are the same
Explanation:
For this calculation we must use the gravitational attraction equation
F = G m M / r²
Where M will use the mass of the Earth, m the mass of the girl and r is the distance of the girl to the center of the earth that we consider spherical
To better visualize things, let's repair the equation a little
F = m (G M / r²)
The amount in parentheses called acceleration of gravity, entered the force called peos
g = G M / r²
F = W
W = m g
When analyzing this equation we see that the variation in the weight of the girl depends on the distance, which is the radius of the earth plus the height where the girl is
r = Re + h
Re = 6.37 10⁶ m
r² = (Re + h)²
r² = Re² (1 + h / Re)²
Let's replace
W = m (GM / Re²) (1+ h / Re)⁻²
W = m g (1+ h / Re)⁻²
This is the exact expression for weight change with height, but let's look at its values for some reasonable heights h = 6300 m (very high mountain)
h / Re = 10
⁻³
(1+ h / Re)⁻² = 0.999⁻²
Therefore, the negligible weight reduction, therefore, for practical purposes the weight does not change with the height of the mountain on Earth
The correct answer is a
Here is your answer:
1. A alternating current is a current "is an electric current which periodically reverses direction." A direct current is a "<span>current which flows only in one direction."
2. They are alike because both are "they both are able to travel in different directions." How they are not alike is that a "alternating current travels in a reverse direction but a direct current can only travel in one direction each current."
Hope this helps!</span>
