Dropping a Tiny Black Hole on Earth

During the recent Venus transit (June 2012), the planet appeared as a tiny black circle moving on the Sun. The black colour on the Sun is because the planet

Black holes in orbit around a normal star are detected from the earth due to the fricitional heating of infalling gas into the black hole, which can reach temperature greater than 10^(6)K . Assuming that the infalling gas can be modelled as a blackbody radiator, then the wavelenght of maximum power lies

Two tiny holes are made in a plastic bucket, one near the middle part and the other just above bottom.When this bucket is filled with water, the water rushes out from the bottom hole much faster than from the upper hole. What conclusion do you get from this observation ?

An object is dropped from an altitude of one Earth radius above Earth’s surface. If M is the mass of Earth and R is its radius. The speed of the object just before it hits Earth is given by: