A proton moves from a location where V = 70 V to a spot where V = -31 V.
(a) What is the change in the proton's kinetic energy?
J
(b) If we replace the proton with an electron, what is the change in kinetic energy?
(a) KE increases by e*(delta V) ,
where delta V = 101 Volts
(b) KE decreases by the same amount as in (a). The electron must possess initial kinetic energy of at least 101*e to reach the -31 V location.
To calculate the change in kinetic energy for a charged particle moving between two points with different electric potentials, we can use the formula:
ΔK = q * (ΔV)
where:
ΔK is the change in kinetic energy
q is the charge of the particle
ΔV is the change in electric potential
(a) Let's calculate the change in kinetic energy for a proton.
Given:
q (proton charge) = +1.6 x 10^-19 C
ΔV = (-31 V) - (70 V) = -101 V
Substituting the values into the formula:
ΔK = (+1.6 x 10^-19 C) * (-101 V)
Calculating:
ΔK = -1.616 x 10^-17 J
Therefore, the change in the proton's kinetic energy is approximately -1.616 x 10^-17 J.
(b) If we replace the proton with an electron, the charge (q) of the particle will change to -1.6 x 10^-19 C. Using the same formula:
ΔK = (-1.6 x 10^-19 C) * (-101 V)
Calculating:
ΔK = 1.616 x 10^-17 J
Therefore, the change in kinetic energy for an electron is approximately 1.616 x 10^-17 J.