Answer: Option A; 9.8 m/s^2
Explanation:
When an object is in the air, and there is no air resistance acting on the object, the only force that will act on the object is the gravitational force (on the vertical axis).
Then, if the only force acting on the object is the gravitational force, the acceleration of the object will be equal to the gravitational acceleration.
We know that the gravitational acceleration is equal to:
g = 9.8m/s^2
Then the acceleration on the vertical axis will be equal to:
a(t) = 9.8m/s^2
The correct option is the first one:
A. 9.8 m/s^2
H line of Calcium spectrum is normally given as 396.9 nm
Now from a distant star we measured it as 398.1 nm
So here this change in the wavelength of distant star is due to Doppler's effect of light as per which when source of light moves towards the observer then the frequency of light received will appear different from its actual frequency
So here we can say as per Doppler's effect of light




given that






so the start is moving away with speed 9.04 * 10^5 m/s because when wavelength is more than the real wavelength then its frequency is less which mean it is moving away from the Earth
Answer:
Explanation:
In Michelson interferometer , two light waves from different directions are made to overlap so that fringes are formed on the screen due to interference . In it, two monochromatic and coherent light are made to overlap which have some path difference or phase difference. They form dark and bright fringes .
Now when a match stick is lit in the path of a wave , the fringes will disappear and an general illumination will be observed on the screen as the light from the lit match stick will not be coherent . Incoherent light can not form stable fringes.
Sound waves travel through the air, liquids, and solids. they transfer energy from the source of the sound to its surroundings
If a = 23 and b = 45
a + b = ?
23 + 45 = 68