Explanation:
Doppler's Effect: If a source is moving towards the observer the frequency of the waves emitted by the source will increase( wavelength will decrease). If the source is moving away from the observer the frequency of the waves emitted by the source will decrease( wavelength will increase). The best example of this is the changing frequency of siren of an ambulance as it moves towards us and then away from us.
The same phenomenon can be observed in celestial objects. When the object will move towards us the wavelength will decrease thus the spectrum will be shifted towards the blue part. This is known as blue shift.
If the object moves away from us the wavelength will increase and thus the spectrum will be shifted towards red part. This is know as Red-shift. This is because red has longer wavelength (620 - 750nm) than blue (450-495nm)
Thus if a galaxy shows us red-shifted spectra it means that it is moving away from us. we have observed this phenomenon in various galaxies thus supporting the expanding universe theory.
The constant angular acceleration (in rad/s2) of the centrifuge is 194.02 rad/s².
<h3> Constant angular acceleration</h3>
Apply the following kinematic equation;
ωf² = ωi² - 2αθ
where;
- ωf is the final angular velocity when the centrifuge stops = 0
- ωi is the initial angular velocity
- θ is angular displacement
- α is angular acceleration
ωi = 3400 rev/min x 2π rad/rev x 1 min/60s = 356.05 rad/s
θ = 52 rev x 2π rad/rev = 326.7 rad
0 = ωi² - 2αθ
α = ωi²/2θ
α = ( 356.05²) / (2 x 326.7)
α = 194.02 rad/s²
Thus, the constant angular acceleration (in rad/s2) of the centrifuge is 194.02 rad/s².
Learn more about angular acceleration here: brainly.com/question/25129606
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Answer:
Option B) C and D
Explanation:
The amount of charge passing through a resistor each second corresponds to the definition of current, so the problem is asking "which resistors have the same amount of current".
Let's keep in mind that:
- When two resistors are in series (=they are connected into the same branch of the circuit), the current flowing through each resistor is the same
- When two resistors are in parallel (=they are connected into different branches), the potential difference across each resistor is the same
Looking at the previous definitions, we have to find the two resistors in the circuit that are connected in series. We see that resistors C and D are in the same branch, so they are in series: therefore, the current flowing through resistor C and D is the same.
Electromagnetic waves differ from mechanical waves in that they do not require a medium to propagate . this means that electromagnetic waves can travel not only through air and solid materials bit also through vacuum of space.
Answer:
70.15 Joule
Explanation:
mass of man, m = 70 kg
intial length, l = 11 m
extension, Δl = 1.5 m
Let K is the spring constant.
In the equilibrium position
mg = K l
70 x 9.8 = K x 11
K = 62.36 N/m
Potential energy stored, U = 0.5 x K x Δl²
U = 0.5 x 62.36 x 1.5 x 1.5
U = 70.15 Joule
