Answer:
The potential difference between the plates is 
Explanation:
Given that,
Distance = 1.4 mm
Electric field strength 
Let the potential difference is V.
We need to calculate the potential difference between the plates
Using formula of electric field


Where, V = potential
d = distance
Put the value into the formula


Hence, The potential difference between the plates is 
Answer:
B A new compound is formed
To solve this problem we will apply the concepts related to energy conservation. From this conservation we will find the magnitude of the amplitude. Later for the second part, we will need to find the period, from which it will be possible to obtain the speed of the body.
A) Conservation of Energy,


Here,
m = Mass
v = Velocity
k = Spring constant
A = Amplitude
Rearranging to find the Amplitude we have,

Replacing,


(B) For this part we will begin by applying the concept of Period, this in order to find the speed defined in the mass-spring systems.
The Period is defined as

Replacing,


Now the velocity is described as,


We have all the values, then replacing,


Answer:
Sound waves are reflected back