Q1. An electron moves in a circular path perpendicular to the constant magnetic field with a magnitude of 2.00 mT. The angular momentum of the electron about the center of the circle is 5.50 multiplied by 10-25 J•s.
(a) Determine the radius of circular path.
(b) Determine the speed of electron.
Q2. A child's helium-filled balloon escapes at sea level and 21 oC. When it reaches an altitude of 3000 m, where the temperature is 3 oC and the pressure only 0.6 atm, what is the ratio of the initial volume to final volume?