Alpha particles from a particular radioactive source have a

Question

Problem: Alpha particles from a particular radioactive source have a speed of 2.85 × 10⁷ m/s. An alpha particle has a mass of 6.64 × 10^-27 kg and a charge of 3.20 × 10^-19 C.

Part A: How large a magnetic field is required to bend the path of the particles into a circle of 0.550 m radius?

I want help to find how large a magnetic field is required to bend the path of the particles into a circle.