Alliptical galaxies lack anything resembling the disk of a spiral galaxy.
The Doppler effect says that the observed wavelength is shortened
when the source is approaching the observer, and lengthened when
the source is receding from the observer.
All we can say about the police car and its siren is that the sound/color
has a shorter wavelength as it approaches us, and a longer wavelength
as it recedes.
Any of these pairs of answers would say that:
A -- A
C -- A
D -- A
or
D -- D
For each of these pairs, the second wavelength is longer than the first one.
(We don't know which pair is the actual one, because we don't know the actual color of the police car.)
Answer:a) The linear speed of the rotating merry-go-round is 1.884 m/s.
b) The acceleration of the rotating merry-go-round device is 
.
Explanation:
a) linear speed of the device:
Distance =
Child seated 1.2 meters from the center, which means that radius ,r = 1.2 meters
Time taken to complete one revolution = 4.0 seconds
The linear speed of the rotating merry-go-round is 1.884 m/s.
b) Acceleration
Linear velocity ,v = 1.884 m/s
The acceleration of the rotating merry-go-round device is .
Off course weight because our weight is equal to for e is equal to mg
Hey there!
This is called stamina. The more of it you have, the longer you can go without getting tired.
Hope this helps!
