What Is the Kinetic Energy of an Alpha Particle at Point B in Electron Volts?

[rcmango]

Homework Statement

Point A is at a potential of +240 V, and point B is at a potential of -120 V. An -particle is a helium nucleus that contains two protons and two neutrons;

the neutrons are electrically neutral. An -particle starts from rest at A and accelerates toward B.

When the -particle arrives at B, what kinetic energy (in electron volts) does it have?
in eV

Homework Equations

The Attempt at a Solution

W = q * (chng in V)

q is the charge stored by a dialectric capacitor.

and change in V is the electric potential difference.

chng in V = Vb - Va = -360 V correct?

so where does the q come from?

 

[chroot]

Let me give you the definition of an "electron volt:"

The energy gained by an electron, in moving through a potential of one volt, is one electron volt.

- Warren

 

[Moetasim]

I would like to provide a response to the content by saying that the kinetic energy of the alpha particle can be calculated using the equation KE = 1/2 mv^2, where m is the mass of the alpha particle and v is its velocity. The charge q is not necessary for this calculation as it is not a factor in kinetic energy. Additionally, the potential difference between points A and B can be used to calculate the acceleration of the alpha particle using the equation a = (Vb-Va)/d, where d is the distance between the two points. From there, the velocity and kinetic energy can be calculated. The unit of kinetic energy is typically given in joules (J), but it can also be expressed in electron volts (eV) by multiplying the value in joules by the conversion factor 6.24 x 10^18 eV/J. Therefore, the kinetic energy of the alpha particle at point B can be calculated using the given information and the above equations.