Q1. An alpha particle with a charge of 2e (e = 1.6 × 10-19 C) and the mass of 4(1.66 × 10-27 kg) is moving at right angles to a uniform magnetic field of 1.20 T. The radius of curvature of the track of the particle is 0.20 m. What is the momentum of alpha particle?
Q2. A small block with a mass of 0.120kg is attached to a cord passing through a hole in a frictionless, horizontal surface. The block is originally revolving at a distance of 0.50 m from the hole with a speed of 0.70m/s. The cord is then pulled from below, shortening the radius of circle in that the block revolves to 0.150 m. At this new distance, the speed of block is observed to be 2.33m/s.
What is the tension in the cord in the original situation
when block has speed v_0 = 0.90 m/s?
What is the tension in the cord in final situation when the block has speed v_1 = 3.00 m/s?
How much work was done by the person who pulled on cord?