Answer: A) <u>Either source or listener must be moving.</u>
Explanation:
Frequencies can shift if an observer is moving relative to the wave’s source. This type of shift is called the Doppler effect (often used to analyze sounds). Think about the sound you hear when a police siren passes you and drives away; as the car increases its distance from you, the pitch of its sound becomes lower. This is because each wave is emitted from a greater distance, causing the wavelength to spread out or increase relative to you, the listener.
maybe yes/maybe No.
Explanation:
cause if the person need a good grades he will going to grab all that he need to grab as a student and studies her lesson.
cause all person has their own reason why he did not do her activity or project because we have a different situations and life..
The distance the ball rolls is given by
<em>x</em> = 1/2 <em>a</em> <em>t</em>²
so that
<em>x</em> = 1/2 * (3.3 m/s²) * (7.5 s)² = 92.8125 m ≈ 93 m