Answer:
1. Revolve around a point
2. Formed from dust and gas particles
3. Exoplanets and associated star orbit a common center of mass
4. Composed of gases found in Jupiter and Saturn
Answer:
a. wavelength of the sound, 
b. observed frequecy, 
Given:
speed of sound source,
= 80 m/s
speed of sound in air or vacuum,
= 343 m/s
speed of sound observed,
= 0 m/s
Solution:
From the relation:
v =
(1)
where
v = velocity of sound
= observed frequency of sound
= wavelength
(a) The wavelength of the sound between source and the listener is given by:
(2)
(b) The observed frequency is given by:


(3)
Using eqn (2) and (3):


La D mijo es blanco por que al pasar con rapides el color se torna blanco
If you take 50 meters and divide by 23.1 seconds, you will get 2.16 meters per second.
So his average speed is 2.16 m/s.