Q. A 2kg rock is released from rest at a height of 29m. ignore air resistance and determine the kinetic energy, gravitational potential energy, and total mechanical energy at each of the following heights: 20m; 15m; 5m; 9m.
Q. If the effective wavelength were 3.9 x 10^3 Earth radii, what would be the (a) frequency and (b) period of the radiation emitted? Ordinarily, electromagnetic radiations do not penetrate very far into conductors such as seawater. Take the Earth's radius to be 6370 km.