Formula for electric potential energy

In summary, the instructor used the equation qV = 1/2 mv^2 to find the velocity of a proton at the end of a velocity selector apparatus with an electric potential of 350 V. This equation represents the energy gained by a charge moving through a potential difference and describes the kinetic energy gained by a body with charge q moving in a region of electric potential v.
  • #1
darksyesider
63
0
In a velocity selector apparatus, i had an electric potential set across two points, and a proton at rest at one end. The potential was 350 V.

My instructor used :

qV = 1/2 mv^2 to find the velocity at the end of the apparatus.

Where did the left hand side of the eqn come from??
 
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  • #2
darksyesider said:
qV = 1/2 mv^2 to find the velocity at the end of the apparatus.

Where did the left hand side of the eqn come from??
That describes the energy gained by a charge q moving through a potential difference V. (The work done by the field on the charge.)
 
  • #4
qv=(0.5)mv^2
This expression indicates Kinetic Energy gained by a body with charge q while moving in a region of Electric potential v.
 
  • #5


The left hand side of the equation, qV, comes from the formula for electric potential energy. Electric potential energy is the energy that a charged particle possesses due to its position in an electric field. It is calculated by multiplying the charge of the particle (q) by the electric potential (V) at its position. In this case, the proton has a charge of q and is at rest, so its electric potential energy is equal to qV. By setting this equal to the kinetic energy of the proton (1/2 mv^2), the instructor was able to solve for the velocity (v) of the proton at the end of the apparatus. This is because the total energy of the proton (potential energy plus kinetic energy) must be conserved throughout its motion in the electric field.
 

What is the formula for electric potential energy?

The formula for electric potential energy is U = qV, where U is the electric potential energy in joules, q is the charge in coulombs, and V is the electric potential in volts.

How is electric potential energy related to electric potential?

Electric potential energy is directly proportional to electric potential. This means that as the electric potential increases, the electric potential energy also increases. The relationship is represented by the formula U = qV.

What units are used for electric potential energy?

Electric potential energy is typically measured in joules (J), which is a unit of energy. However, it can also be measured in electron volts (eV), which is a unit of energy commonly used in atomic and nuclear physics.

How is the formula for electric potential energy derived?

The formula for electric potential energy is derived from the definition of electric potential energy as the work done per unit charge to move a charge from one point to another in an electric field. It is also based on the relationship between electric potential, electric field, and charge.

Can the formula for electric potential energy be used for both positive and negative charges?

Yes, the formula for electric potential energy can be used for both positive and negative charges. The only difference is the sign of the charge (positive or negative) in the formula. A positive charge will have a positive potential energy, while a negative charge will have a negative potential energy.

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