Question

Scientists study a radioactive source that produces a stream of positively-charged particles moving with different speeds along the x-axis. The stream enters a box with a uniform magnetic field B = 0.1 T directed along the z-axis and a uniform electric field E of unknown strength and direction. Scientists observe that the particles that move with the speed of 2 m/s are not deflected in the box at all.

A. Find the direction and the strength of the electric field in the box.

Scientists allow only undeflected particles to leave the box through a small opening and enter a big chamber that contains only magnetic field B = 0.1 T along the z-axis.

B. Describe the trajectory of the particles in the chamber.

C. Scientists notice that the particles completely reverse their direction of motion in 0.1 ms after entering the chamber. Assuming that their particle’s charge is 1.6 x 10^-19 C, determine the mass of the particles.

Answer 1

.....