An electron has been accelerated from rest through a potential difference of 1000 V. a. What is its kinetic energy, in electron volts? b. What is its kinetic energy, in joules? c. What is its speed?

a. 1000ev.

b. 1.602*10⁻¹⁶ Joules.

c. 3.52 * 10¹⁴ m/s

Explanation:

(a)

Kinetic Energy of the electron in Electron volt = eV

Ek = eV ... Equation 1

Where Ek = Kinetic Energy of the electron in electron volt, V = potential difference of the electron, e = charge of electron.

Given: V = 1000 V,

Substituting these values into equation 1,

Ek = 1000 eV

(b) Kinetic Energy in Joules

Ek = eV

Where e = 1.602 * 10⁻¹⁹ joules, V = 1000 V,

Ek = 1.602 * 10⁻¹⁹*1000

Ek = 1.602*10⁻¹⁶ Joules.

(c) Ek = 1/2mv²

m = √ (2Ek/m) ... Equation 2

Where m = mass of the electron, v = velocity of the electron.

Given: Ek = 1.602*10⁻¹⁶

Constant: m = 9.11*10⁻³¹ kg.

Substituting into equation 2

v = √ (2*1.602*10⁻¹⁶/9.11*10⁻³¹)

v = 3.52 * 10¹⁴ m/s