Answer:
The source is at a distance of 4.56 m from the first point.
Solution:
As per the question:
Separation distance between the points, d = 11.0 m
Sound level at the first point, L = 66.40 dB
Sound level at the second point, L'= 55.74 dB
Now,

where

I = Intensity of sound
Now,

Similarly,

Now,




Solving the above quadratic eqn, we get:
R = 4.56 m
Since it moves 5 m/s faster every second, after 20 seconds it's moving 100 m/s faster than when it started speeding up.
If it was moving at 14 m/s when the acceleration began, it's moving at 114 m/s at the end of the 20 seconds. Its velocity is <em>114 m/s North.</em>
That's 255 mph !
Answer:
A) receding from the earth
B) 
Explanation:
- A) receding from the earth
The wavelength went from 434.1nm to 438.6nm, there was an increase in wavelength (also knowecn as redshift due to the doppler efft), this increase is due to the fact that the source that emits the radiation (the distant galaxy) is moving away and therefore the light waves it emits are "stretched", causing us to see a wavelength greater than the original.
- B)

to calculate the relative speed we use the following formula:

where
is the speed of light:
is the wavelength emited by the source, and
is the wavelength measured on earth.
we substitute all the values and do the calculations:

the relative speed is: 
Answer:
The First is an example of acceleration, the second is an example of velocity
Answer:
We could get the time taken by the ball to return back to earth, using the formula:
s = u t + ½ a t², where
s = displacement of the body moving with initial velocity u, acceleration 'a' in time t.
In the present case s=0 (as the ball returns back to starting time)
u= 30 m/s; a = -10 m/s² ( negative sign as a is in opposite direction to u); t=?
0 = 30 t - ½ ×10 ×t²; ==> 5 t = 30, t= 6 second.
So ball will return back after 6 second after being thrown up.
Explanation:
I looked it up
Hope this helps