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

Where,
v = Speed of sound
f' = Reflected frequency
f = Emitted Frequency 
 = Speed of the object
 = Speed of the object 
Assuming that the speed of the medium is the speed of sound of 343m / s, we will then have that:


 
        
             
        
        
        
Particles vibrate parallel to the direction the sound travels. It's a longitudinal wave.
        
                    
             
        
        
        
Answer:
1- The acceleration of the object is larger in magnitude the smaller the radius of the circle. 
Explanation:
The acceleration of an object in a circular path is

As can be seen from the equation, if the radius of the circle is decreases, the magnitude of the acceleration increases. 
As for the direction of the acceleration, it is always towards the center, and it is always perpendicular to the direction of the velocity. 
 
        
             
        
        
        
Explanation:
It is a good idea to start with room temperature water in the calorimeter because the room temperature water helps to determine the heating up/cooling down because of the environment as the experiment takes place. Because the calorimeter heat is the same as the heat of the water.
 
        
                    
             
        
        
        
Answer:
the cell is the smallest unit