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:
The compass needle will point towards the magnetic field, so if it is in a magnet it will most likely spin around in circles.
Explanation:
Answer:
The answer to the question is
The object would fall 57.625 m in the first 5 seconds
Explanation:
To solve the question, we note that
the height of fall = 490 ft = 149.352 m
Time to touch the ground = 7 seconds
We are required to find out how far the object falls in the first 5 seconds
We apply the relation
S = u·t + 0.5×g·t ² = We then have
149.352 = U×7+0.5*9.81*49 From where u = -13 m/s
Therefore to find how far it falls in the first 5 seconds, we have
-13*5 + 0.5*9.81*25 = 57.625 m
The answer is a.12.5kg because i just did the test and it was correct.
hope this helps
The strength of the gravitational field is given by:
where
G is the gravitational constant
M is the Earth's mass
r is the distance measured from the centre of the planet.
In our problem, we are located at 300 km above the surface. Since the Earth radius is R=6370 km, the distance from the Earth's center is:
And now we can use the previous equation to calculate the field strength at that altitude:
And we can see this value is a bit less than the gravitational strength at the surface, which is
.
