To solve this problem we will apply the concepts related to the Doppler effect. The Doppler effect is the change in the perceived frequency of any wave movement when the emitter, or focus of waves, and the receiver, or observer, move relative to each other. Mathematically it can be described as

Here,
=frequency received by detector
=frequency of wave emitted by source
=velocity of detector
=velocity of source
v=velocity of sound wave
Replacing we have that,


Therefore the frequencty that will hear the passengers is 422Hz
C
Explanation:
that's just what I learned in school
Answer:
2. at the lowest point
Explanation:
The motion of the pendulum is a continuous conversion between kinetic energy (KE) and gravitational potential energy (GPE). This is because the mechanical energy of the pendulum, which is sum of KE and GPE, is constant:
E = KE + GPE = const.
Therefore, when KE is maximum, GPE is minimum, and viceversa.
So, the point of the motion where the KE is maximum is where the GPE is minimum: and since the GPE is directly proportional to the heigth of the bob:

we see that GPE is minimum when the bob is at the lowest point,so the correct answer is
2. at the lowest point
Answer:
1 second
Explanation:
h = −16t² + 32t
When, h = 16
16 = −16t² + 32t
Divide each of the numbers by 16
1 = -1t² + 2t
Rearrange the equation
1t²-2t+1 = 0
Solving by the quadratic formula, we get

So, time taken by the dolphin to jump out of the water and touch the trainer's hand is 1 second.
Answer: For the first part the answer is Radio Waves and the second part’s answer is gamma ray.