# a-Particle (the nucleus of a helium atom), the kinetic energy of which is 8 * 10 ^ -17 J, flies into a uniform magnetic

**a-Particle (the nucleus of a helium atom), the kinetic energy of which is 8 * 10 ^ -17 J, flies into a uniform magnetic field with an induction of 0.1 T perpendicular to its lines of force. Determine the force acting on the particle, the radius of the circle along which it moves, and the period of its revolution.**

In order to find a formula for a solution, you need to look at what is given to us:

B = 0.1 T;

sin A = 1;

q = 3.2 * 10 ^ -19 C;

m = 6.64 * 10-27 Kg;

Ek = 8 * 10 ^ -17 J;

Let’s write down the formulas that we will use:

E = m * u ^ 2/2;

u ^ 2 = 2 * E / m;

It should be noted that u is a constant: u = 1.5523 * 10 ^ 5 m / s.

Find F by the formula:

F = q * u * B * sin A = q * √ (2 * E / m) * B * sinA;

Let’s substitute:

F = 3.2 * 10 ^ -19 * √ (2 * 8 * 10 ^ -17 / 6.64 * 10 – 27) * 0.1 * 1;

F = 4.967 * 10 ^ -15 H;

Let’s find R, according to the formula:

R = m * u / (q * B);

Let’s substitute:

R = 6.64 * 10 ^ -27 * √ (2 * 8 * 10 ^ -17 / 6.64 * 10 – 27) / (3.2 * 10 ^ -19 * 0.1);

R = 0.0322 m;

R = 3.22 cm.

Find T, by the formula:

T = 2pi * R / u;

T = 2pi * 0.0322 / (1.5523 * 10 ^ 5);

T = 1.3 * 10 ^ -6 s.

Answer: T = 1.3 * 10 ^ -6 s.