A proton is at rest at the plane vertical boundary of a region containing a uniform vertical magnetic fi eld B. An alpha particle moving horizontally makes a head-on elastic collision with the proton. Immediately after the collision, both particles enter the magnetic fi eld, moving perpendicular to the direction of the fi eld. The radius of the protons trajectory is R. Find the radius of the alpha particles trajectory. The mass of the alpha particle is four times that of the proton, and its charge is twice that of the proton.
PHYS Notes Week 7 Feb 2226 Electric Charge Particles have either a positive or negative charge Combining these particles into atoms/molecules result in three possibilities Negatively charged: object contains more negative particles than positive particles Positively charged: object contains more positive particles than negative particles Electrically neutral: object contains equal amounts of positive and negative particles Nature prefers neutral charges The terms "positive" and "negative" don't mean anything; they just refer to the fact that the charges are opposite
