186. A proton and an alpha particle $\alpha$ with equal kinetic energies enter a magnetic field of magnitude $B$ and move in circular paths perpendicular to the magnetic field. Which of the following statements about these two particles is correct? (Mass of alpha particle $\alpha$ is 4 times the mass of the proton.)
- [1)] The speed of $\alpha$ is 2 times the speed of the proton.
- [2)] The momentum of the proton equals the momentum of particle $\alpha$.
- [3)] The radius of the path of $\alpha$ equals the radius of the path of the proton.
- [4)] The electromagnetic force on the proton is 2 times the electromagnetic force on particle $\alpha$.