Tidal forces are caused by the difference in the gravitational acceleration across an object. Estimate the tidal acceleration across the body of an astronaut (Newtonian approximation) if she is falling through an event horizon of a stellar mass black hole compared to the black hole at the centre of the Milky Way. Assume your astronaut is 1.6m tall and use 3 M and 4 106 M for the masses of the black holes.

For the same two black holes in the previous question, calculate the time for the unfortunate astronaut to complete her journey to the centre of the black hole, from her viewpoint. As she crosses the event horizon what changes will she see in the external universe?