Question1
1. The moon has a diameter of 3.48 106 m and is a distance of 3.85 108 m from the earth. The sun has a diameter of 1.39 109 m and is 1.50 1011 m from the earth.
(a) Establish (in radians) angles subtended by the moon and the sun, as measured by a person standing on the earth.
(b) Based on your answers to part (a), decide if a total eclipse of the sun is really “total.” Give proper reasoning.
(c) Find out the ratio, expressed as a percentage, of the apparent circular area of the moon to the apparent circular area of sun.
2. A particle of mass m and charge q moves in a circular path in a magnetic field
B. explain that its kinetic energy is proportional to r 2, the square of the radius of curvature of its path.
3. Prove that the angular momentum of particle is L = qBr 2 about the center of the circle.