O Bluish ("blue")
B Bluish-white ("blue-white")
A White with bluish tinged ("white")
F White ("yellow-white")
G Light yellow ("yellow")
K Light orange ("orange")
M Reddish orange ("red")
The answer will be c
speed is equals to distance over time
<em>number of waves that pass a given point in one second is called <u>frequency..</u></em>
Answer:

Explanation:
Given:
- original frequency of sound wave,

- speed of the sound source,

- original speed of sound wave from the source,

<u>According to the Doppler's effect:</u>

The sound is reflected from the wall and the source is moving towards the wall and observer is also riding the same source.
The velocity of the observer,


Answer:
d=1.25 m
Explanation:
fd=.5mv2-.5mv1; 10(d)=.5(50)(.5)-0; 10(d)=12.5; d=12.5/10; d=1.25 m