Understanding the Concepts

* Electric Potential: Electric potential (measured in volts, V) is the amount of potential energy per unit charge at a specific point in an electric field.

* Work Done by Electric Field: The work done by an electric field on a charge is equal to the negative change in the potential energy of the charge.

* Potential Energy and Charge: The potential energy (U) of a charge (q) in an electric field is given by U = qV, where V is the electric potential.

Calculation

1. Find the change in potential energy:

* Initial potential energy (U₁): U₁ = qV₁ = (1.602 x 10⁻¹⁹ C) * (140 V)

* Final potential energy (U₂): U₂ = qV₂ = (1.602 x 10⁻¹⁹ C) * (-80 V)

* Change in potential energy (ΔU) = U₂ - U₁

2. Calculate the work done:

* Work done (W) = -ΔU

Let's plug in the numbers:

* ΔU = [(1.602 x 10⁻¹⁹ C) * (-80 V)] - [(1.602 x 10⁻¹⁹ C) * (140 V)] = -3.52 x 10⁻¹⁷ J

* W = - (-3.52 x 10⁻¹⁷ J) = 3.52 x 10⁻¹⁷ J

Answer: The electric field does 3.52 x 10⁻¹⁷ J of work in moving the proton from the 140 V point to the -80 V point.