Answer:
The number of polarizer needed so transmitted light has at least 12% intensity = 17
Explanation:
Given :
Angle between incident light and optic axis of polarizer = 20°
Given that, the transmission axis of each additional analyzer is rotated 20° relative to the transmission axis of the previous one
According to the malus law,
The intensity of the transmitted light passes through the polarizer is proportional to the square of the cosine of angle between the transmission axis to the optic axis.
⇒
Where, transmitted intensity through polarizer, incident intensity of the light.
Given in question, all the time 20°
By calculation ∴
After 1st polarizer,
∴
Now we need to multiply all the time 0.883 until we get 0.12 (relative 20° angle given in question)
After 17th polarizer we get 0.1205 ≅ 0.12
%
Means we get 12% intensity after 17th polarizing disk.
Power is the rate of doing work or using energy.
The unit of power is the watt.
1 watt = 1 joule per second
Answer:
70 km/h
Explanation:
Let the velocity of car A is v km/h, thus the velocity of car B is (v - 20) km/h.
They meet after 3 hours.
Distance traveled by car A in 3 hours = v x 3 = 3 v
Distance traveled by car B in 3 hours = (v - 20) x 3 = 3v - 60
Total distance traveled is 480 km
So, 3 v + 3 v - 60 = 480
6 v - 60 = 480
6 v = 540
v = 90 km/h
Thus, the speed of car A is 90 km/h and the speed of car B is 90 - 20 = 70 km/h.
Answer:
Part a)
the tension force is equal to the weight of the crate
Part b)
tension force is more than the weight of the crate while accelerating upwards
tension force is less than the weight of crate if it is accelerating downwards
Explanation:
Part a)
When large crate is suspended at rest or moving with uniform speed then it is given as
here since speed is constant or it is at rest
so we will have
so the tension force is equal to the weight of the crate
Part b)
Now let say the crate is accelerating upwards
now we can say
so tension force is more than the weight of the crate
Now if the crate is accelerating downwards
so tension force is less than the weight of crate if it is accelerating downwards
In Building, there are a host of protective devices that are installed to protect lives and properties, one of them is the Lightning Conductor that a metal rod mounted on a structure and intended to protect the structure from a lightning strike. It works on the principle of induction
<h3>
Principle of Operation of Lightning Conductor</h3>
The lightning conductor works on the principle of induction:
- When a charged cloud passes by the building hosting the Lightning conductor, it gets a charge opposite to that of the cloud through the process of induction.
- They are Typically made from copper material.
Most Lightening conductors are made from copper materials.
Learn about Lightning Conductor:
brainly.com/question/2824044