Answer:
From Newton's 2nd Law, we have 
. Substituting given values, we have:
Given :
Height from which ball is dropped , h = 40 m .
Acceleration due to gravity , g= 10 m/s² .
Initial velocity , u = 0 m/s .
To Find :
Velocity when ball covered 20 m and velocity when it hit the ground .
Solution :
Now , height when ball covered 20 m distance is , 40 - 20 = 20 m .
By equation of motion :
Now , distance covered when body reaches ground is , 40 m .
Putting value h = 40 m in above equation , we get :
Hence , this is the required solution .
Due to rotation of Earth on each day, our East & west gets change in every half day, and comes in it's initial state after a day. So, Stars which are in east relative to a stationary object in the Universe, will be in west relative to Earth after some time, and it changes our view of stars
Hope this helps!
Energy E of EM radiation is given by the equation E=hf, where h is Planck's constant and f is frequency. It means energy E and frequency f are proportional so as we increase the frequency, energy also increases. Also, the relationship between the wavelength and frequency is c=λ*f where λ is the wavelength and f is frequency and c is the speed of light. This tells us the wavelength and frequency are inversely proportional. So as we increase the frequency the wavelength is getting smaller. So as we go from left to right the frequency increases, energy also increases and the wavelength is decreasing. Or, on the left side we should have low frequency, low radiant energy, and long wavelength. On the right side we should have high frequency, high radiant energy and low wavelength. That is the third graph.
