A charged particle is moving in a uniform magnetic field. Which of the following statements concerning the magnetic force exerted on the particle is false?
A) It does not change the kinetic energy of the particle.
B) It can act only on a particle in motion.
C) It increases the speed of the particle.
D) It changes the velocity of the particle.
E) It does no work on the particle.
What is your thinking on this? The magnetic force acts perpendicular to the path of motion.
answer is c
D) it changes the velocioty of the particle, because to find the velocity we need to know the mass, the gravational pull and the heigh of the particle (potential energy) and if any one of these things change then the velocity also changes. And because the magnetic force is acting on the partical the gravational pull would change meaning the veolcity changes.