Answer:
292.3254055 W/m²
469.26267 V/m

Explanation:
P = Power of bulb = 90 W
d = Diameter of bulb = 7 cm
r = Radius = 
= Permittivity of free space = 
c = Speed of light = 
The intensity is given by

5% of this energy goes to the visible light so the intensity is

The visible light intensity at the surface of the bulb is 292.3254055 W/m²
Energy density of the wave is

Energy density is also given by

The amplitude of the electric field at this surface is 469.26267 V/m
Amplitude of a magnetic field is given by

The amplitude of the magnetic field at this surface is 
Answer:
A. 50 Hz
B. 2 m/s
Explanation:
We'll begin by converting 20 ms to s. This can be obtained as follow:
1000 ms = 1 s
Therefore,
20 ms = 20 ms × 1 s / 1000 ms
20 ms = 0.02 s
Next, we shall convert the value of the wavelength (i.e 4cm) to m. This can be obtained as follow:
100 cm = 1 m
Therefore,
4 cm = 4 cm × 1 m / 100 cm
4 cm = 0.04 m
A. Determination of the frequency.
Period (T) = 0.02 s
Frequency (f) =?
f = 1 / T
f = 1 / 0.02
f = 50 Hz
Therefore, the frequency of the wave is 50 Hz
B. Determination of the velocity.
Wavelength (λ) = 0.04 m
Frequency (f) = 50 Hz
Velocity (v) =?
v = λf
V = 0.04 × 50
v = 2 m/s
Therefore, the velocity of the wave is 2 m/s
My guess is they need it to turn co2 into oxygen
Answer:
Ethan's tangential speed is twice as Rebecca's.
Explanation:
Let
be the distance from the center of the platform to Rebecca's horse,
Rebecca's tangential speed,
the Ethan's tangential speed and
the merry-go-round angular speed. The distance from the center of the platform to Ethan's horse is
. The angular speed is related to the tangential speed by the equation:

Since the angular speed is the same for Ethan and Rebecca, we have that:

Now, solving for
we get:

It means that Ethan's tangential speed is twice as Rebecca's.