Answer:
The transmitted intensity through all polarizers is 
Explanation:
According to Malu's law the intensity of a polarized light having an initial intensity 
is mathematically represented as
Now considering the polarizer(The polarizing disk) the equation above becomes
Where n is the number of polarizers
Substituting 
for the initial intensity 3 for the n and 20° for the angle of rotation
Answer:
Explanation:
The power of each of the speakers is 0.535 W. At a distance d intensity of sound can be found by the following formula
Intensity of sound = Power / 4π d²
= .535 / 4 x 3.14 x (27.3/2)²
= 2.286 x 10⁻⁴ J m⁻² s⁻¹
Intensity of sound due to other source = 5.715 x 10⁻⁵J m⁻² s⁻¹
Total intensity = 2 x 2.286 x 10⁻⁴J m⁻² s⁻¹
= 4.57 x 10⁻⁴J m⁻² s⁻¹
b ) In this case, man is standing at distances 18.15 m and 9.15 m from the sources .
The total intensity of sound reaching him is as follows
0.535 / (4 π x18.15² ) + 0.535 / (4 π x9.15² )
= 1.293 x 10⁻⁴ + 5.087 x 10⁻⁴
= 6.38 x 10⁻⁴J m⁻² s⁻¹
In some unusual applications of unusual components, I can think of unusual electric circuits where a switch may be connected in parallel with a device in order to control it.
But I'm sure this is not what's intended in a question on the high-school level.
Until you get in a situation with tricky applications in a tricky circuit, your switches will always be connect <em>in series</em> with the devices they control.
Answer:
about 602 milliseconds
Explanation:
The motion can be approximated by the equation ...
y = -4.9t^2 -22.8t +15.5
where t is the time since the arrow was released, and y is the distance above the ground.
When y=0, the arrow has hit the ground.
Using the quadratic formula, we find ...
t = (-(-22.8) ± √((-22.8)^2 -4(-4.9)(15.5)))/(2(-4.9))
= (22.8 ± √823.64)/(-9.8)
The positive solution is ...
t ≈ 0.60195193
It takes about 602 milliseconds for the arrow to reach the ground.
