Very often you must have seen traffic police catching motorists and scooter drivers who drive fast and fine them. Does fine for speeding depend on average speed or instantaneous speed ? Explain.

You may have seen in a circus a motorcyclist driving in vertical loops inside a ‘death- well’ (a hollow spherical chamber with holes, so the spectators can watch from outside). Explain clearly why the motorcyclist does not drop down when he is at the uppermost point, with no support from below. What is the minimum speed required at the uppermost position to perform a vertical loop if the radius of the chamber is 25 m ?