Answer:19.5 m
Explanation:
Given
coefficient of kinetic Friction 
Initial speed 
Friction is present so it tries to stop to the object and stops it completely after moving certain distance let say s
maximum deceleration provided by friction is


using equation of motion

where 




Answer:
The value is 
Explanation:
From the question we are told that
The area is 
The root mean square value is 
The time taken is 
Generally the energy is mathematically represented as

=> 
=> 
<span>Well iron, nickle, and cobalt can be natural magnets because they have minerals or metals that generate a stable magnetic field without artificial inducement. A piece of wood cannot be a natural magnet because it does not have metals or minerals that allow it to generate a stable magnetic field. Other types of metals that are magnetic are man made.</span>
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.
I believe it’s nuclear energy.