time for some gravity! except if have no idea what’s going on, could someone ? : )

Ametal ball with a mass of 0.028 kg is dropped from rest at a height of 1.0 meters above the ground. assuming the energy in the ball is conserved, how much kinetic energy will the ball have when it is 0.5 meters above the ground?

Which wave would cause destructive interference at every point of the wavelength and completely cancel out the wave?

Patients with brain tumors may elect to have a procedure known as gamma knife. in a typical gamma knife procedure gamma rays are directed toward a tumor with contact to surrounding tissues. limiting contact between gamma rays and healthy tissue is important because