Answer:
77J
Explanation:
Not really an explanation to this, I just had this lesson last year and remembered it.
Hope I helped! ☺
Because dark line spectra result from passing white light through ionized gasses and plasmas, which is what the atmosphere of stars are made of. These frequencies are scattered by the star's atmosphere as it leaves the surface (photosphere) of the star, and don't make it to earth.
Answer:
Explanation:
Given that:
the initial angular velocity 
angular acceleration
= 4.44 rad/s²
Using the formula:

Making t the subject of the formula:

where;

∴

t = 0.345 s
b)
Using the formula:

here;
= angular displacement
∴



Recall that:
2π rad = 1 revolution
Then;
0.264 rad = (x) revolution

x = 0.042 revolutions
c)
Here; force = 270 N
radius = 1.20 m
The torque = F * r

However;
From the moment of inertia;

given that;
I = 84.4 kg.m²

For re-tardation; 
Using the equation



t = 0.398s
The required time it takes= 0.398s
These two forces are called action and reaction forces and are the subject of Newton's third law of motion. Formally stated, Newton's third law is: For every action, there is an equal and opposite reaction. The statement means that in every interaction, there is a pair of forces acting on the two interacting objects.
Answer:
the smallest angle from the antennas is <em>47.3°</em>
Explanation:
We first need to write the expression for the relation between the wavelength (λ) and the frequency (f) of the wave, and then solve for the wavelength.
Therefore, the relation is:
λ = c /f
where
- c is the speed of light constant
- λ is the wavelength
- f is the frequency
Thus,
λ = (3 × 10⁸ m/s) / (3.4 MHz)
= (3 × 10⁸ m/s) / (3.4 MHz)(10⁶ Hz/1 MHz)
= 88.235 m
Therefore, the smallest angle measured (from the north of east) from the antennas for the constructive interference of the two-radio wave can be calculated as
θ = sin⁻¹(λ / d)
where
- d is the distance between the two radio antennas
Thus,
θ = sin⁻¹(88.235 / 120)
<em>θ = 47.3 °</em>
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Therefore, the smallest angle from the antennas, measured north of east, at which constructive interference of two radio waves occurs is <em>47.3 °</em>.