Answer:19.5 J
Explanation:
Given
mass of block=3 kg
angular frequency=20 rad/sec
spring constant 
we know total energy remain conserved
Where 
=kinetic energy
=potential Energy
When mass reaches amplitude its velocity becomes zero
there is only potential energy which is equal to Total energy
Answer: Option (b) is the correct answer.
Explanation:
It is given that a positive test charge q is released from rest at a distance r away from a charge of +Q and a distance 2r which is away from a charge of +2Q.
Then test charge to the right immediately after being released.
Therefore, the net force will be as follows.
F = 
= 
= 
F = > 0
Thus, we can conclude that the test charge move to the right immediately after being released.
<span>10 hertz
Hertz is the frequency of oscillation which is the number of oscillations per second. So if something takes 0.10 s per oscillation, divide 1 second by the period to get the frequency. So
1 / 0.10s = 10 1/s = 10 Hertz
Therefore the object is vibrating at 10 hertz.</span>
Answer:
Doppler shift of the starlight
Explanation:
To predict the movement of a star, we compare the spectra of elements found in star (H, He Na etc.), first spectra which are obtained from star and second spectra from laboratory. If spectral lines of the spectra obtained from star, are shifting towards red end (called red shift) then star is going away from earth and if shifting is towards blue (called blue shift), then star is approaching the earth. This is Doppler's shift.
Answer:
<em>T</em><em>h</em><em>e</em><em>r</em><em>e</em><em> </em><em>are</em><em> </em><em>t</em><em>wo hydrogen </em><em>atom</em><em> </em><em>in</em><em> </em><em>all</em><em> </em><em>the</em><em> </em><em>reactants</em><em>.</em>
