I attached the full question.
We know that for a parallel-plate capacitor the surface charge density is given by the following formula:

Where V is the voltage between the plates and d is separation.
Voltage is by definition:

Voltage is analog to the mechanical work done by the force.
Above formula is correct only If the field is constant, and we can assume that it is since no function has been given.
The charge density would then be:

Please note that elecric permittivity of air is very close to elecric permittivity of vacum, it is common to use them <span>interchangeably</span>.
As we use the Kinetic energy and the equation is 1/2mv^2, changing its mass will change its speed and its energy. So more mass, more speed more energy. also the gravitational potential energy; mass x gravity x height; more mass and more height more speed as it go down to the slope! Hope it helps!
Assuming an ideal gas, the speed of sound depends on temperature
only. Air is almost an ideal gas.
Assuming the temperature of 25°C in a "standard atmosphere", the
density of air is 1.1644 kg/m3, and the speed of sound is 346.13 m/s.
The velocity can't be specified, since the question gives no information
regarding the direction of the sound.
Answer:
motion energy
Explanation:
motion wnergy is the sum of potential and kinetic energy