Answer:
The amplitude is
Explanation:
From the question we are told that
The frequency of when sound is approaching observer is 
The frequency as the move away from observer is 
The time between the pitch are 
Here you are the observer and your friends are the source of the sound
The period is mathematically evaluated as

as it is the time to complete one oscillation which from on highest pitch to the next highest pitch
Now T can also be mathematically represented as

Where
is the angular velocity
=> 
=> 
Now using Doppler Effect,
The source of the sound is approaching the observer
The


Where A is the amplitude
So when the source is moving away from the observer
Here
is the fundamental frequency
Dividing the both equation we have




=> 

Answer:
D. Tidal energy is replaced naturally by the Moon's gravity.
Explanation:
The reason tidal energy is considered a renewable energy resource is that Tidal energy is replaced naturally by the Moon's gravity. The Moon's gravity creates bulges on the side of Earth that is closest and farthest from the Moon. These bulges also pull water causing high tides in those areas. As the Earth rotates these areas experience low tide while the areas that had low tide now experience high tide. This constant shift creates tidal energy every day, which is replenished naturally.
Yes the winds are moving in a straight line
Answer:

Explanation:
We are asked to find the cyclist's initial velocity. We are given the acceleration, final velocity, and time, so we will use the following kinematic equation.

The cyclist is acceleration at 1.2 meters per second squared. After 10 seconds, the velocity is 16 meters per second.
= 16 m/s - a= 1.2 m/s²
- t= 10 s
Substitute the values into the formula.

Multiply.


We are solving for the initial velocity, so we must isolate the variable
. Subtract 12 meters per second from both sides of the equation.


The cyclist's initial velocity is <u>4 meters per second.</u>