Answer:
The force is 
Explanation:
From the question we are told that
The mass of the block is 
The coefficient of static friction is 
The coefficient of kinetic friction is 
The normal force acting on the block is
substituting values
Given that the force we are to find is the force required to get the block to start moving then the force acting against this force is the static frictional force which is mathematically evaluated as
substituting values
Now for this block to move the force require is equal to 
i.e
=>
I think the corect answer would be C. When a police officer receives information that you are speeding in your vehicle, she is using the frequency of the wave to measure the Doppler Effect. As the speed of a vehicle increases, the greater the change of the frequency of the waves would be transmitted to the radar guns which is being used by the police officer. Doppler effect is an effect that is observed in sound and light waves as these waves move away or to the direction of the observer. This is being used in many applications like in astronomy, weather balloons, the radar guns,and for underwater researches.
The primary colors of light are red, blue and green.
There are the pigments like yellow, magenta and cyan that are the mixture of two primary colors.
For example, magenta is a mixture of red and blue color. Thus, it reflects the red and blue color. Also, magneta absorbs the green color.
These type of colors that reflects two primary colors and absorb one color are known as secondary pigments.
Hence, 2nd option is the correct answer.
Answer:
Effective temperature, Doppler velocity
Explanation:
Since star behave localy as a blackbody, Wíen's displacement law can be use in order to determine its effective temperature. From the spectrum it will be take the wavelength at which is the peak of emission greater in the continuum
Then, the maximum peak of emission (
) will be replace in the next equation of the Wien's displacement law:
(1)
Where T is the effective temperature of the star.
Spectral lines will be shifted to the blue part of the spectrum if the source of the observed light is moving toward the observer, or to the red part of the spectrum when is moving away from the observer (that is known as the Doppler effect).
By using that shift in the spectral lines it can be determine the Doppler velocity.
(2)
Where 
is the wavelength shift, 
is the wavelength at rest, v is the velocity of the source and c is the speed of light.
