In separate experiments, four different particles each start from far away with the same speed and impinge directly on a gold nucleus. The masses and charges of the particles are Rank the particles according to the distance of closest approach to the gold nucleus, from smallest to largest.

Question

In separate experiments, four different particles each start from far away with the same speed and impinge directly on a gold nucleus. The masses and charges of the particles are  Rank the particles according to the distance of closest approach to the gold nucleus, from smallest to largest.

Quizplus · Accepted Answer

The distance of closest approach is dependent on both the speed and the charge of the particle, but not its mass. The charge of particle 3 is the largest, and so it will have the smallest closest approach. Particles 1 and 2 have the same charge and speed, so their closest approach will be the same. Particle 4 has the smallest charge and so will have the largest closest approach. Therefore, the ranking is: 3, then 1 and 2 tie, then 4.

In Separate Experiments, Four Different Particles Each Start from Far