An electron in a magnetic field with an induction of 0.02 T described a circle with a radius of 15 cm.

An electron in a magnetic field with an induction of 0.02 T described a circle with a radius of 15 cm. Find the speed of the electron.

Given:

B = 0.02 T – magnetic field induction;

R = 15 centimeters = 0.15 meters – the radius of the circle described by the electron;

m = 9.1 * 10 ^ -31 kilograms is the mass of an electron;

e = 1.6 * 10 ^ -19 Coulomb – electron charge.

It is required to determine v – the speed of the electron.

v = e * B * R / m = 1.6 * 10 ^ -19 * 0.02 * 0.15 / (9.1 * 10 ^ -31) = 5.27 * 10 ^ -4 * 10 ^ – 19/10 ^ 31 = 5.27 * 10 ^ 8 m / s.

Answer: the speed of the electron is 5.27 * 10 ^ 8 m / s.